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  • Verizon Wireless Supports its Mission-Critical Employee Portal with MySQL

    - by Bertrand Matthelié
    Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Cambria","serif"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin;} Verizon Wireless, the #1 mobile carrier in the United States, operates the nation’s largest 3G and 4G LTE network, with the most subscribers (109 millions) and the highest revenue ($70.2 Billion in 2011). Verizon Wireless built the first wide-area wireless broadband network and delivered the first wireless consumer 3G multimedia service in the US, and offers global voice and data services in more than 200 destinations around the world. To support 4.2 million daily wireless transactions and 493,000 calls and emails transactions produced by 94.2 million retail customers, Verizon Wireless employs over 78,000 employees with area headquarters across the United States. The Business Challenge Seeing the stupendous rise in social media, video streaming, live broadcasting…etc which redefined the scope of technology, Verizon Wireless, as a technology savvy company, wanted to provide a platform to its employees where they could network socially, view and host microsites, stream live videos, blog and provide the latest news. The IT team at Verizon Wireless had abundant experience with various technology platforms to support the huge number of applications in the company. However, open-source products weren’t yet widely used in the organization and the team had the ambition to adopt such technologies and see if the architecture could meet Verizon Wireless’ rigid requirements. After evaluating a few solutions, the IT team decided to use the LAMP stack for Vzweb, its mission-critical, 24x7 employee portal, with Drupal as the front end and MySQL on Linux as the backend, and for a few other internal websites also on MySQL. The MySQL Solution Verizon Wireless started to support its employee portal, Vzweb, its online streaming website, Vztube, and internal wiki pages, Vzwiki, with MySQL 5.1 in 2010. Vzweb is the main internal communication channel for Verizon Wireless, while Vztube hosts important company-wide webcasts regularly for executive-level announcements, so both channels have to be live and accessible all the time for its 78,000 employees across the United States. However during the initial deployment of the MySQL based Intranet, the application experienced performance issues. High connection spikes occurred causing slow user response time, and the IT team applied workarounds to continue the service. A number of key performance indexes (KPI) for the infrastructure were identified and the operational framework redesigned to support a more robust website and conform to the 99.985% uptime SLA (Service-Level Agreement). The MySQL DBA team made a series of upgrades in MySQL: Step 1: Moved from MyISAM to InnoDB storage engine in 2010 Step 2: Upgraded to the latest MySQL 5.1.54 release in 2010 Step 3: Upgraded from MySQL 5.1 to the latest GA release MySQL 5.5 in 2011, and leveraging MySQL Thread Pool as part of MySQL Enterprise Edition to scale better After making those changes, the team saw a much better response time during high concurrency use cases, and achieved an amazing performance improvement of 1400%! In January 2011, Verizon CEO, Ivan Seidenberg, announced the iPhone launch during the opening keynote at Consumer Electronic Show (CES) in Las Vegas, and that presentation was streamed live to its 78,000 employees. The event was broadcasted flawlessly with MySQL as the database. Later in 2011, Hurricane Irene attacked the East Coast of United States and caused major life and financial damages. During the hurricane, the team directed more traffic to its west coast data center to avoid potential infrastructure damage in the East Coast. Such transition was executed smoothly and even though the geographical distance became longer for the East Coast users, there was no impact in the performance of Vzweb and Vztube, and the SLA goal was achieved. “MySQL is the key component of Verizon Wireless’ mission-critical employee portal application,” said Shivinder Singh, senior DBA at Verizon Wireless. “We achieved 1400% performance improvement by moving from the MyISAM storage engine to InnoDB, upgrading to the latest GA release MySQL 5.5, and using the MySQL Thread Pool to support high concurrent user connections. MySQL has become part of our IT infrastructure, on which potentially more future applications will be built.” To learn more about MySQL Enterprise Edition, Get our Product Guide.

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  • CLR via C# 3rd Edition is out

    - by Abhijeet Patel
    Time for some book news update. CLR via C#, 3rd Edition seems to have been out for a little while now. The book was released in early Feb this year, and needless to say my copy is on it’s way. I can barely wait to dig in and chew on the goodies that one of the best technical authors and software professionals I respect has in store. The 2nd edition of the book was an absolute treat and this edition promises to be no less. Here is a brief description of what’s new and updated from the 2nd edition. Part I – CLR Basics Chapter 1-The CLR’s Execution Model Added about discussion about C#’s /optimize and /debug switches and how they relate to each other. Chapter 2-Building, Packaging, Deploying, and Administering Applications and Types Improved discussion about Win32 manifest information and version resource information. Chapter 3-Shared Assemblies and Strongly Named Assemblies Added discussion of TypeForwardedToAttribute and TypeForwardedFromAttribute. Part II – Designing Types Chapter 4-Type Fundamentals No new topics. Chapter 5-Primitive, Reference, and Value Types Enhanced discussion of checked and unchecked code and added discussion of new BigInteger type. Also added discussion of C# 4.0’s dynamic primitive type. Chapter 6-Type and Member Basics No new topics. Chapter 7-Constants and Fields No new topics. Chapter 8-Methods Added discussion of extension methods and partial methods. Chapter 9-Parameters Added discussion of optional/named parameters and implicitly-typed local variables. Chapter 10-Properties Added discussion of automatically-implemented properties, properties and the Visual Studio debugger, object and collection initializers, anonymous types, the System.Tuple type and the ExpandoObject type. Chapter 11-Events Added discussion of events and thread-safety as well as showing a cool extension method to simplify the raising of an event. Chapter 12-Generics Added discussion of delegate and interface generic type argument variance. Chapter 13-Interfaces No new topics. Part III – Essential Types Chapter 14-Chars, Strings, and Working with Text No new topics. Chapter 15-Enums Added coverage of new Enum and Type methods to access enumerated type instances. Chapter 16-Arrays Added new section on initializing array elements. Chapter 17-Delegates Added discussion of using generic delegates to avoid defining new delegate types. Also added discussion of lambda expressions. Chapter 18-Attributes No new topics. Chapter 19-Nullable Value Types Added discussion on performance. Part IV – CLR Facilities Chapter 20-Exception Handling and State Management This chapter has been completely rewritten. It is now about exception handling and state management. It includes discussions of code contracts and constrained execution regions (CERs). It also includes a new section on trade-offs between writing productive code and reliable code. Chapter 21-Automatic Memory Management Added discussion of C#’s fixed state and how it works to pin objects in the heap. Rewrote the code for weak delegates so you can use them with any class that exposes an event (the class doesn’t have to support weak delegates itself). Added discussion on the new ConditionalWeakTable class, GC Collection modes, Full GC notifications, garbage collection modes and latency modes. I also include a new sample showing how your application can receive notifications whenever Generation 0 or 2 collections occur. Chapter 22-CLR Hosting and AppDomains Added discussion of side-by-side support allowing multiple CLRs to be loaded in a single process. Added section on the performance of using MarshalByRefObject-derived types. Substantially rewrote the section on cross-AppDomain communication. Added section on AppDomain Monitoring and first chance exception notifications. Updated the section on the AppDomainManager class. Chapter 23-Assembly Loading and Reflection Added section on how to deploy a single file with dependent assemblies embedded inside it. Added section comparing reflection invoke vs bind/invoke vs bind/create delegate/invoke vs C#’s dynamic type. Chapter 24-Runtime Serialization This is a whole new chapter that was not in the 2nd Edition. Part V – Threading Chapter 25-Threading Basics Whole new chapter motivating why Windows supports threads, thread overhead, CPU trends, NUMA Architectures, the relationship between CLR threads and Windows threads, the Thread class, reasons to use threads, thread scheduling and priorities, foreground thread vs background threads. Chapter 26-Performing Compute-Bound Asynchronous Operations Whole new chapter explaining the CLR’s thread pool. This chapter covers all the new .NET 4.0 constructs including cooperative cancelation, Tasks, the aralle class, parallel language integrated query, timers, how the thread pool manages its threads, cache lines and false sharing. Chapter 27-Performing I/O-Bound Asynchronous Operations Whole new chapter explaining how Windows performs synchronous and asynchronous I/O operations. Then, I go into the CLR’s Asynchronous Programming Model, my AsyncEnumerator class, the APM and exceptions, Applications and their threading models, implementing a service asynchronously, the APM and Compute-bound operations, APM considerations, I/O request priorities, converting the APM to a Task, the event-based Asynchronous Pattern, programming model soup. Chapter 28-Primitive Thread Synchronization Constructs Whole new chapter discusses class libraries and thread safety, primitive user-mode, kernel-mode constructs, and data alignment. Chapter 29-Hybrid Thread Synchronization Constructs Whole new chapter discussion various hybrid constructs such as ManualResetEventSlim, SemaphoreSlim, CountdownEvent, Barrier, ReaderWriterLock(Slim), OneManyResourceLock, Monitor, 3 ways to solve the double-check locking technique, .NET 4.0’s Lazy and LazyInitializer classes, the condition variable pattern, .NET 4.0’s concurrent collection classes, the ReaderWriterGate and SyncGate classes.

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  • FairScheduling Conventions in Hadoop

    - by dan.mcclary
    While scheduling and resource allocation control has been present in Hadoop since 0.20, a lot of people haven't discovered or utilized it in their initial investigations of the Hadoop ecosystem. We could chalk this up to many things: Organizations are still determining what their dataflow and analysis workloads will comprise Small deployments under tests aren't likely to show the signs of strains that would send someone looking for resource allocation options The default scheduling options -- the FairScheduler and the CapacityScheduler -- are not placed in the most prominent position within the Hadoop documentation. However, for production deployments, it's wise to start with at least the foundations of scheduling in place so that you can tune the cluster as workloads emerge. To do that, we have to ask ourselves something about what the off-the-rack scheduling options are. We have some choices: The FairScheduler, which will work to ensure resource allocations are enforced on a per-job basis. The CapacityScheduler, which will ensure resource allocations are enforced on a per-queue basis. Writing your own implementation of the abstract class org.apache.hadoop.mapred.job.TaskScheduler is an option, but usually overkill. If you're going to have several concurrent users and leverage the more interactive aspects of the Hadoop environment (e.g. Pig and Hive scripting), the FairScheduler is definitely the way to go. In particular, we can do user-specific pools so that default users get their fair share, and specific users are given the resources their workloads require. To enable fair scheduling, we're going to need to do a couple of things. First, we need to tell the JobTracker that we want to use scheduling and where we're going to be defining our allocations. We do this by adding the following to the mapred-site.xml file in HADOOP_HOME/conf: <property> <name>mapred.jobtracker.taskScheduler</name> <value>org.apache.hadoop.mapred.FairScheduler</value> </property> <property> <name>mapred.fairscheduler.allocation.file</name> <value>/path/to/allocations.xml</value> </property> <property> <name>mapred.fairscheduler.poolnameproperty</name> <value>pool.name</value> </property> <property> <name>pool.name</name> <value>${user.name}</name> </property> What we've done here is simply tell the JobTracker that we'd like to task scheduling to use the FairScheduler class rather than a single FIFO queue. Moreover, we're going to be defining our resource pools and allocations in a file called allocations.xml For reference, the allocation file is read every 15s or so, which allows for tuning allocations without having to take down the JobTracker. Our allocation file is now going to look a little like this <?xml version="1.0"?> <allocations> <pool name="dan"> <minMaps>5</minMaps> <minReduces>5</minReduces> <maxMaps>25</maxMaps> <maxReduces>25</maxReduces> <minSharePreemptionTimeout>300</minSharePreemptionTimeout> </pool> <mapreduce.job.user.name="dan"> <maxRunningJobs>6</maxRunningJobs> </user> <userMaxJobsDefault>3</userMaxJobsDefault> <fairSharePreemptionTimeout>600</fairSharePreemptionTimeout> </allocations> In this case, I've explicitly set my username to have upper and lower bounds on the maps and reduces, and allotted myself double the number of running jobs. Now, if I run hive or pig jobs from either the console or via the Hue web interface, I'll be treated "fairly" by the JobTracker. There's a lot more tweaking that can be done to the allocations file, so it's best to dig down into the description and start trying out allocations that might fit your workload.

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  • Stay on Schedule in Chrome with DayHiker

    - by Matthew Guay
    Do you keep your schedule and tasks in Google Calendar?  Here’s a handy extension for Google Chrome that can keep you on top of your appointments without having to open Google Calendar in another tab. Integrate Google Calendar with Chrome DayHiker is a handy extension for Google Chrome that can help you stay on schedule in your browser.  Desktop applications typically can keep you notified easier with popups or alerts, but webapps require you to visit them to view your information.  DayHiker takes the best of both, and can make your Google Calendar work more like a desktop application. To get started, open the DayHiker page from the Chrome Extensions Gallery (link below), and click Install.  Confirm you wish to install it at the prompt. Now you’ll have a new extension button in your Chrome toolbar.  Click the calendar icon to view your Google Calendar.  You’ll need to be signed into your Google account for your calendar to display; click the key icon to select your account if it doesn’t show your appointments automatically. If you’re signed into multiple Google accounts, such as your public Gmail and a Google Apps account, you can select the calendar you wish and click Continue. Now you can quickly see your upcoming appointments.  Simply hover over the icon to see your upcoming events.  Or, just glance at it to see if there are any appointments coming up, as the indicator icon will change colors to show how long you have until your next appointment. Click the icon to see more information about your appointments. Or, click the Add link to add a new appointment.  If you need to edit the appointment details, click Edit Details and the appointment will open in Google Calendar for you to edit. You can also view and manage your tasks in Google Calendar.  Click the checkmark icon, and then add or check-off tasks directly from the extension pane. You can also set an alarm clock in DayHiker.  Click the green circle icon, and then enter the time for the alarm to go off.  Strangely it will only chime if the extension pane is left open, so if you click anywhere else in the browser or even switch to another program it will not chime.   If you’d like to customize DayHiker’s settings, right-click on it and select Options, or select Options in the Chrome Extensions page.  Here you can customize your badges and the DayHiker icon, or enter a custom domain for your Google Apps Pro calendar.   Conclusion If you rely on Google Calendar to stay on top of your schedule, DayHiker can help you stay scheduled and know what’s coming up.  We wish DayHiker supported multiple calendars so we could combine our Google Apps calendars with our personal Google Calendar, but even still, it is a very useful tool.  Whether you’re a tightly scheduled person or just like to jot down to-dos and keep track of them, this extension will help you do this efficiently with familiar Google tools. Link Download DayHiker from the Chrome Extensions Gallery Similar Articles Productive Geek Tips Configure Disk Defragmenter Schedule in Windows 7 or VistaSchedule Updates for Windows Media CenterOpen Multiple Sites Without Reopening the Menus in FirefoxFind a Website’s Actual Location with Chrome FlagsSubscribe to RSS Feeds in Chrome with a Single Click TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips HippoRemote Pro 2.2 Xobni Plus for Outlook All My Movies 5.9 CloudBerry Online Backup 1.5 for Windows Home Server Dual Boot Ubuntu and Windows 7 What is HTML5? Default Programs Editor – One great tool for Setting Defaults Convert BMP, TIFF, PCX to Vector files with RasterVect Free Identify Fonts using WhatFontis.com Windows 7’s WordPad is Actually Good

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  • Microsoft Silverlight 4 Business Application Development: Beginner's Guide

    Build enterprise-ready business applications with Silverlight An introduction to building enterprise-ready business applications with Silverlight quickly. Get hold of the basic tools and skills needed to get started in Silverlight application development. Integrate different media types, taking the RIA experience further with Silverlight, and much more! Rapidly manage business focused controls, data, and business logic connectivity. A suite of business applications will be built over the course of the book and all examples will be geared around real-world useful application developments, enabling .NET developers to focus on getting started in business application development using Silverlight. In Detail Microsoft Silverlight is a programmable web browser plug-in that enables features including animation, vector graphics, and audio-video playback--features that characterize Rich Internet Applications. Silverlight makes possible the development of RIA applications in familiar .NET languages such as C# and VB.NET. Silverlight is a great (and growing) Line of Business platform and is increasingly being used to build business applications. Silverlight 3 made a big step in LOB; Silverlight 4 builds upon this further. This book will enable .NET developers to feel the pulse of business application development with Silverlight quickly. This book is not a general Silverlight 3/4 overview book. It is uniquely aimed at developers who require an introduction to building business applications with Silverlight. This book will focus on building a suite of real-world, useful business applications in a practical hands-on approach. This book is for .Net developers, providing the answers to many questions that are encountered when creating business applications in Silverlight, ultimately enabling rapid development with ease! This book teaches you how to build business applications with Silverlight 3 and 4. Building a suite of applications, it begins by introducing you to the basic tools and skills needed to get started in Silverlight development. It then dives deeply into the world of business application development, covering all the required concepts needed to build sophisticated business applications and provide a rich user experience. Chapters include: building a public website, adding rich media to the website, incorporating RIA into your website, and among others. By following the practical steps in this book, you will learn what's needed to create rich business applications--from the creation of a Silverlight application, to enhancing your application with rich media and connecting your Silverlight application to various Data Sources. What you will learn from this book Learn the basic tools and skills needed to get started in Silverlight 4 business application development. Discover how to enhance your Silverlight business applications with rich data such as sound and video. Know when and how to customize your data in Silverlight using important data controls. Understand how your Silverlight business applications can connect to various Data Sources. Deliver your Silverlight business application in a variety of forms.   Interesting? Read the chapter 1 Getting Started for free!! Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • SPARC T4-4 Delivers World Record First Result on PeopleSoft Combined Benchmark

    - by Brian
    Oracle's SPARC T4-4 servers running Oracle's PeopleSoft HCM 9.1 combined online and batch benchmark achieved World Record 18,000 concurrent users while executing a PeopleSoft Payroll batch job of 500,000 employees in 43.32 minutes and maintaining online users response time at < 2 seconds. This world record is the first to run online and batch workloads concurrently. This result was obtained with a SPARC T4-4 server running Oracle Database 11g Release 2, a SPARC T4-4 server running PeopleSoft HCM 9.1 application server and a SPARC T4-2 server running Oracle WebLogic Server in the web tier. The SPARC T4-4 server running the application tier used Oracle Solaris Zones which provide a flexible, scalable and manageable virtualization environment. The average CPU utilization on the SPARC T4-2 server in the web tier was 17%, on the SPARC T4-4 server in the application tier it was 59%, and on the SPARC T4-4 server in the database tier was 35% (online and batch) leaving significant headroom for additional processing across the three tiers. The SPARC T4-4 server used for the database tier hosted Oracle Database 11g Release 2 using Oracle Automatic Storage Management (ASM) for database files management with I/O performance equivalent to raw devices. This is the first three tier mixed workload (online and batch) PeopleSoft benchmark also processing PeopleSoft payroll batch workload. Performance Landscape PeopleSoft HR Self-Service and Payroll Benchmark Systems Users Ave Response Search (sec) Ave Response Save (sec) Batch Time (min) Streams SPARC T4-2 (web) SPARC T4-4 (app) SPARC T4-2 (db) 18,000 0.944 0.503 43.32 64 Configuration Summary Application Configuration: 1 x SPARC T4-4 server with 4 x SPARC T4 processors, 3.0 GHz 512 GB memory 5 x 300 GB SAS internal disks 1 x 100 GB and 2 x 300 GB internal SSDs 2 x 10 Gbe HBA Oracle Solaris 11 11/11 PeopleTools 8.52 PeopleSoft HCM 9.1 Oracle Tuxedo, Version 10.3.0.0, 64-bit, Patch Level 031 Java Platform, Standard Edition Development Kit 6 Update 32 Database Configuration: 1 x SPARC T4-4 server with 4 x SPARC T4 processors, 3.0 GHz 256 GB memory 3 x 300 GB SAS internal disks Oracle Solaris 11 11/11 Oracle Database 11g Release 2 Web Tier Configuration: 1 x SPARC T4-2 server with 2 x SPARC T4 processors, 2.85 GHz 256 GB memory 2 x 300 GB SAS internal disks 1 x 100 GB internal SSD Oracle Solaris 11 11/11 PeopleTools 8.52 Oracle WebLogic Server 10.3.4 Java Platform, Standard Edition Development Kit 6 Update 32 Storage Configuration: 1 x Sun Server X2-4 as a COMSTAR head for data 4 x Intel Xeon X7550, 2.0 GHz 128 GB memory 1 x Sun Storage F5100 Flash Array (80 flash modules) 1 x Sun Storage F5100 Flash Array (40 flash modules) 1 x Sun Fire X4275 as a COMSTAR head for redo logs 12 x 2 TB SAS disks with Niwot Raid controller Benchmark Description This benchmark combines PeopleSoft HCM 9.1 HR Self Service online and PeopleSoft Payroll batch workloads to run on a unified database deployed on Oracle Database 11g Release 2. The PeopleSoft HRSS benchmark kit is a Oracle standard benchmark kit run by all platform vendors to measure the performance. It's an OLTP benchmark where DB SQLs are moderately complex. The results are certified by Oracle and a white paper is published. PeopleSoft HR SS defines a business transaction as a series of HTML pages that guide a user through a particular scenario. Users are defined as corporate Employees, Managers and HR administrators. The benchmark consist of 14 scenarios which emulate users performing typical HCM transactions such as viewing paycheck, promoting and hiring employees, updating employee profile and other typical HCM application transactions. All these transactions are well-defined in the PeopleSoft HR Self-Service 9.1 benchmark kit. This benchmark metric is the weighted average response search/save time for all the transactions. The PeopleSoft 9.1 Payroll (North America) benchmark demonstrates system performance for a range of processing volumes in a specific configuration. This workload represents large batch runs typical of a ERP environment during a mass update. The benchmark measures five application business process run times for a database representing large organization. They are Paysheet Creation, Payroll Calculation, Payroll Confirmation, Print Advice forms, and Create Direct Deposit File. The benchmark metric is the cumulative elapsed time taken to complete the Paysheet Creation, Payroll Calculation and Payroll Confirmation business application processes. The benchmark metrics are taken for each respective benchmark while running simultaneously on the same database back-end. Specifically, the payroll batch processes are started when the online workload reaches steady state (the maximum number of online users) and overlap with online transactions for the duration of the steady state. Key Points and Best Practices Two Oracle PeopleSoft Domain sets with 200 application servers each on a SPARC T4-4 server were hosted in 2 separate Oracle Solaris Zones to demonstrate consolidation of multiple application servers, ease of administration and performance tuning. Each Oracle Solaris Zone was bound to a separate processor set, each containing 15 cores (total 120 threads). The default set (1 core from first and third processor socket, total 16 threads) was used for network and disk interrupt handling. This was done to improve performance by reducing memory access latency by using the physical memory closest to the processors and offload I/O interrupt handling to default set threads, freeing up cpu resources for Application Servers threads and balancing application workload across 240 threads. See Also Oracle PeopleSoft Benchmark White Papers oracle.com SPARC T4-2 Server oracle.com OTN SPARC T4-4 Server oracle.com OTN PeopleSoft Enterprise Human Capital Management oracle.com OTN PeopleSoft Enterprise Human Capital Management (Payroll) oracle.com OTN Oracle Solaris oracle.com OTN Oracle Database 11g Release 2 Enterprise Edition oracle.com OTN Disclosure Statement Oracle's PeopleSoft HR and Payroll combined benchmark, www.oracle.com/us/solutions/benchmark/apps-benchmark/peoplesoft-167486.html, results 09/30/2012.

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  • Keep it Professional &ndash; Multiple Environments

    - by AjarnMark
    I have certainly been reading blogs a whole lot more than writing them the last several weeks, and it’s about time I got back to writing.  I have been collecting several topics and references for blog posts…some of which will probably just never get written as the timeliness of the topics fade over time.  Nonetheless, I’m back, and I think it is time to revive my Doing Business Right series, this time coming from the slant of managing a development team rather than the previous angle of being self-employed.  First up: separating Dev, Test, and Prod. A few months ago, Colin Stasiuk (@BenchmarkIT) wrote a great post about separating your Dev, Test/UAT, and Prod environments.  This post covers all the important points such as removing Developer access from both PROD and UAT, and the importance of proper deployment (a.k.a. promotion) procedures.  I won’t repeat it all here, go read the original!  But what I do want to address is what I believe to be the #1 excuse people use for not having separate environments:  Money.  I discussed this briefly in my comment on Colin’s post at the time, but let me repeat it here and expand on it a bit. Don’t let the size of your company or the size of its budget dictate whether you do things professionally or not.  I am convinced that most developers and development teams would agree that it is a best practice to have separate environments for development, testing, and production (a.k.a. Live).  So why don’t they?  Because they think that it means separate servers which means more money.  While having separate physical servers for the different environments would be ideal, it is not an absolute requirement in order to make this work.  Here are a few ideas: Use multiple instances of SQL Server and multiple Web Sites with Headers or Ports.  For no additional fees* you can install multiple instances of SQL Server on the same machine.  This gives you a nice separation, allowing you to even use the same database names as will appear in PROD, yet isolating the data and security access.  And in IIS, you can create multiple Web Sites on the same server just by using Host Headers or different port numbers to separate them.  This approach does still pose the risk of non-Prod environments impacting performance on Prod, but when your application is busy enough for that to be a concern, you can probably afford one of the other options. Use desktop PCs instead of servers.  Instead of investing in full server-grade hardware, you can mimic the separate environments on old desktop PCs and at least get functional equivalency, if not performance matching.  The last I checked, Microsoft did not require separate licensing for SQL Server if that installation was used exclusively for dev or test purposes*.  There may be some version or performance differences between this approach and what you have in Prod, but you have isolated test from impacting Prod resources this way. Virtualization.  This is of course one of the hot topics of the day, and I would be remiss if I did not suggest this.  It is quite easy these days to setup virtual machines so that, again, your environments are fairly isolated from one another, and you retain all the security and procedural benefits of having separate environments. So the point is, keep your high professional standards intact.  You don’t need to compromise on using proper procedure just because you work in a small company with a small budget.  Keep doing things the right way! By the way, where I work, our DEV environment is not on a server.  All development is done on the developer’s individual workstation where it can be isolated from other developers’ work for the duration of writing the code, but also where the developers have to reconcile (merge) differences in code under concurrent development.  This usually means that each change is executed multiple times (once per developer to update their environments with the latest changes from others) giving us an extra, informal. test deployment before even going to the Test/UAT server.  It also means that if the network goes down, the developers can continue to hum along because they are not dependent on networked resources.  In fact, they will likely be even more productive because they aren’t being interrupted by email…but that’s another post I need to write. * I am not a lawyer, nor a licensing specialist, but it appeared to be so the last time I checked.  When in doubt, consult an expert on the topic.

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  • College Courses through distance learning

    - by Matt
    I realize this isn't really a programming question, but didn't really know where to post this in the stackexchange and because I am a computer science major i thought id ask here. This is pretty unique to the programmer community since my degree is about 95% programming. I have 1 semester left, but i work full time. I would like to finish up in December, but to make things easier i like to take online classes whenever I can. So, my question is does anyone know of any colleges that offer distance learning courses for computer science? I have been searching around and found a few potential classes, but not sure yet. I would like to gather some classes and see what i can get approval for. Class I need: Only need one C SC 437 Geometric Algorithms C SC 445 Algorithms C SC 473 Automata Only need one C SC 452 Operating Systems C SC 453 Compilers/Systems Software While i only need of each of the above courses i still need to take two more electives. These also have to be upper 400 level classes. So i can take multiple in each category. Some other classes I can take are: CSC 447 - Green Computing CSC 425 - Computer Networking CSC 460 - Database Design CSC 466 - Computer Security I hoping to take one or two of these courses over the summer. If not, then online over the regular semester would be ok too. Any help in helping find these classes would be awesome. Maybe you went to a college that offered distance learning. Some of these classes may be considered to be graduate courses too. Descriptions are listed below if you need. Thanks! Descriptions Computer Security This is an introductory course covering the fundamentals of computer security. In particular, the course will cover basic concepts of computer security such as threat models and security policies, and will show how these concepts apply to specific areas such as communication security, software security, operating systems security, network security, web security, and hardware-based security. Computer Networking Theory and practice of computer networks, emphasizing the principles underlying the design of network software and the role of the communications system in distributed computing. Topics include routing, flow and congestion control, end-to-end protocols, and multicast. Database Design Functions of a database system. Data modeling and logical database design. Query languages and query optimization. Efficient data storage and access. Database access through standalone and web applications. Green Computing This course covers fundamental principles of energy management faced by designers of hardware, operating systems, and data centers. We will explore basic energy management option in individual components such as CPUs, network interfaces, hard drives, memory. We will further present the energy management policies at the operating system level that consider performance vs. energy saving tradeoffs. Finally we will consider large scale data centers where energy management is done at multiple layers from individual components in the system to shutting down entries subset of machines. We will also discuss energy generation and delivery and well as cooling issues in large data centers. Compilers/Systems Software Basic concepts of compilation and related systems software. Topics include lexical analysis, parsing, semantic analysis, code generation; assemblers, loaders, linkers; debuggers. Operating Systems Concepts of modern operating systems; concurrent processes; process synchronization and communication; resource allocation; kernels; deadlock; memory management; file systems. Algorithms Introduction to the design and analysis of algorithms: basic analysis techniques (asymptotics, sums, recurrences); basic design techniques (divide and conquer, dynamic programming, greedy, amortization); acquiring an algorithm repertoire (sorting, median finding, strong components, spanning trees, shortest paths, maximum flow, string matching); and handling intractability (approximation algorithms, branch and bound). Automata Introduction to models of computation (finite automata, pushdown automata, Turing machines), representations of languages (regular expressions, context-free grammars), and the basic hierarchy of languages (regular, context-free, decidable, and undecidable languages). Geometric Algorithms The study of algorithms for geometric objects, using a computational geometry approach, with an emphasis on applications for graphics, VLSI, GIS, robotics, and sensor networks. Topics may include the representation and overlaying of maps, finding nearest neighbors, solving linear programming problems, and searching geometric databases.

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  • xna orbit camera troubles

    - by user17753
    I have a Model named cube to which I load in LoadContent(): cube = Content.Load<Model>("untitled");. In the Draw Method I call DrawModel: private void DrawModel(Model m, Matrix world) { foreach (ModelMesh mesh in m.Meshes) { foreach (BasicEffect effect in mesh.Effects) { effect.EnableDefaultLighting(); effect.View = camera.View; effect.Projection = camera.Projection; effect.World = world; } mesh.Draw(); } } camera is of the Camera type, a class I've setup. Right now it is instantiated in the initialization section with the graphics aspect ratio and the translation (world) vector of the model, and the Draw loop calls the camera.UpdateCamera(); before drawing the models. class Camera { #region Fields private Matrix view; // View Matrix for Camera private Matrix projection; // Projection Matrix for Camera private Vector3 position; // Position of Camera private Vector3 target; // Point camera is "aimed" at private float aspectRatio; //Aspect Ratio for projection private float speed; //Speed of camera private Vector3 camup = Vector3.Up; #endregion #region Accessors /// <summary> /// View Matrix of the Camera -- Read Only /// </summary> public Matrix View { get { return view; } } /// <summary> /// Projection Matrix of the Camera -- Read Only /// </summary> public Matrix Projection { get { return projection; } } #endregion /// <summary> /// Creates a new Camera. /// </summary> /// <param name="AspectRatio">Aspect Ratio to use for the projection.</param> /// <param name="Position">Target coord to aim camera at.</param> public Camera(float AspectRatio, Vector3 Target) { target = Target; aspectRatio = AspectRatio; ResetCamera(); } private void Rotate(Vector3 Axis, float Amount) { position = Vector3.Transform(position - target, Matrix.CreateFromAxisAngle(Axis, Amount)) + target; } /// <summary> /// Resets Default Values of the Camera /// </summary> private void ResetCamera() { speed = 0.05f; position = target + new Vector3(0f, 20f, 20f); projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.PiOver4, aspectRatio, 0.5f, 100f); CalculateViewMatrix(); } /// <summary> /// Updates the Camera. Should be first thing done in Draw loop /// </summary> public void UpdateCamera() { Rotate(Vector3.Right, speed); CalculateViewMatrix(); } /// <summary> /// Calculates the View Matrix for the camera /// </summary> private void CalculateViewMatrix() { view = Matrix.CreateLookAt(position,target, camup); } I'm trying to create the camera so that it can orbit the center of the model. For a test I am calling Rotate(Vector3.Right, speed); but it rotates almost right but gets to a point where it "flips." If I rotate along a different axis Rotate(Vector3.Up, speed); everything seems OK in that direction. So I guess, can someone tell me what I'm not accounting for in the above code I wrote? Or point me to an example of an orbiting camera that can be fixed on an arbitrary point?

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  • Explaining Explain Plan Notes for Auto DOP

    - by jean-pierre.dijcks
    I've recently gotten some questions around "why do I not see a parallel plan" while Auto DOP is on (I think)...? It is probably worthwhile to quickly go over some of the ways to find out what Auto DOP was thinking. In general, there is no need to go tracing sessions and look under the hood. The thing to start with is to do an explain plan on your statement and to look at the parameter settings on the system. Parameter Settings to Look At First and foremost, make sure that parallel_degree_policy = AUTO. If you have that parameter set to LIMITED you will not have queuing and we will only do the auto magic if your objects are set to default parallel (so no degree specified). Next you want to look at the value of parallel_degree_limit. It is typically set to CPU, which in default settings equates to the Default DOP of the system. If you are testing Auto DOP itself and the impact it has on performance you may want to leave it at this CPU setting. If you are running concurrent statements you may want to give this some more thoughts. See here for more information. In general, do stick with either CPU or with a specific number. For now avoid the IO setting as I've seen some mixed results with that... In 11.2.0.2 you should also check that IO Calibrate has been run. Best to simply do a: SQL> select * from V$IO_CALIBRATION_STATUS; STATUS        CALIBRATION_TIME ------------- ---------------------------------------------------------------- READY         04-JAN-11 10.04.13.104 AM You should see that your IO Calibrate is READY and therefore Auto DOP is ready. In any case, if you did not run the IO Calibrate step you will get the following note in the explain plan: Note -----    - automatic DOP: skipped because of IO calibrate statistics are missing One more note on calibrate_io, if you do not have asynchronous IO enabled you will see:  ERROR at line 1: ORA-56708: Could not find any datafiles with asynchronous i/o capability ORA-06512: at "SYS.DBMS_RMIN", line 463 ORA-06512: at "SYS.DBMS_RESOURCE_MANAGER", line 1296 ORA-06512: at line 7 While this is changed in some fixes to the calibrate procedure, you should really consider switching asynchronous IO on for your data warehouse. Explain Plan Explanation To see the notes that are shown and explained here (and the above little snippet ) you can use a simple explain plan mechanism. There should  be no need to add +parallel etc. explain plan for <statement> SELECT PLAN_TABLE_OUTPUT FROM TABLE(DBMS_XPLAN.DISPLAY()); Auto DOP The note structure displaying why Auto DOP did not work (with the exception noted above on IO Calibrate) is like this: Automatic degree of parallelism is disabled: <reason> These are the reason codes: Parameter -  parallel_degree_policy = manual which will not allow Auto DOP to kick in  Hint - One of the following hints are used NOPARALLEL, PARALLEL(1), PARALLEL(MANUAL) Outline - A SQL outline of an older version (before 11.2) is used SQL property restriction - The statement type does not allow for parallel processing Rule-based mode - Instead of the Cost Based Optimizer the system is using the RBO Recursive SQL statement - The statement type does not allow for parallel processing pq disabled/pdml disabled/pddl disabled - For some reason (alter session?) parallelism is disabled Limited mode but no parallel objects referenced - your parallel_degree_policy = LIMITED and no objects in the statement are decorated with the default PARALLEL degree. In most cases all objects have a specific degree in which case Auto DOP will honor that degree. Parallel Degree Limited When Auto DOP does it works you may see the cap you imposed with parallel_degree_limit showing up in the note section of the explain plan: Note -----    - automatic DOP: Computed Degree of Parallelism is 16 because of degree limit This is an obvious indication that your are being capped for this statement. There is one quite interesting one that happens when you are being capped at DOP = 1. First of you get a serial plan and the note changes slightly in that it does not indicate it is being capped (we hope to update the note at some point in time to be more specific). It right now looks like this: Note -----    - automatic DOP: Computed Degree of Parallelism is 1 Dynamic Sampling With 11.2.0.2 you will start seeing another interesting change in parallel plans, and since we are talking about the note section here, I figured we throw this in for good measure. If we deem the parallel (!) statement complex enough, we will enact dynamic sampling on your query. This happens as long as you did not change the default for dynamic sampling on the system. The note looks like this: Note ----- - dynamic sampling used for this statement (level=5)

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  • JDK bug migration: components and subcomponents

    - by darcy
    One subtask of the JDK migration from the legacy bug tracking system to JIRA was reclassifying bugs from a three-level taxonomy in the legacy system, (product, category, subcategory), to a fundamentally two-level scheme in our customized JIRA instance, (component, subcomponent). In the JDK JIRA system, there is technically a third project-level classification, but by design a large majority of JDK-related bugs were migrated into a single "JDK" project. In the end, over 450 legacy subcategories were simplified into about 120 subcomponents in JIRA. The 120 subcomponents are distributed among 17 components. A rule of thumb used was that a subcategory had to have at least 50 bugs in it for it to be retained. Below is a listing the component / subcomponent classification of the JDK JIRA project along with some notes and guidance on which OpenJDK email addresses cover different areas. Eventually, a separate incidents project to host new issues filed at bugs.sun.com will use a slightly simplified version of this scheme. The preponderance of bugs and subcomponents for the JDK are in library-related areas, with components named foo-libs and subcomponents primarily named after packages. While there was an overall condensation of subcomponents in the migration, in some cases long-standing informal divisions in core libraries based on naming conventions in the description were promoted to formal subcomponents. For example, hundreds of bugs in the java.util subcomponent whose descriptions started with "(coll)" were moved into java.util:collections. Likewise, java.lang bugs starting with "(reflect)" and "(proxy)" were moved into java.lang:reflect. client-libs (Predominantly discussed on 2d-dev and awt-dev and swing-dev.) 2d demo java.awt java.awt:i18n java.beans (See beans-dev.) javax.accessibility javax.imageio javax.sound (See sound-dev.) javax.swing core-libs (See core-libs-dev.) java.io java.io:serialization java.lang java.lang.invoke java.lang:class_loading java.lang:reflect java.math java.net java.nio (Discussed on nio-dev.) java.nio.charsets java.rmi java.sql java.sql:bridge java.text java.util java.util.concurrent java.util.jar java.util.logging java.util.regex java.util:collections java.util:i18n javax.annotation.processing javax.lang.model javax.naming (JNDI) javax.script javax.script:javascript javax.sql org.openjdk.jigsaw (See jigsaw-dev.) security-libs (See security-dev.) java.security javax.crypto (JCE: includes SunJCE/MSCAPI/UCRYPTO/ECC) javax.crypto:pkcs11 (JCE: PKCS11 only) javax.net.ssl (JSSE, includes javax.security.cert) javax.security javax.smartcardio javax.xml.crypto org.ietf.jgss org.ietf.jgss:krb5 other-libs corba corba:idl corba:orb corba:rmi-iiop javadb other (When no other subcomponent is more appropriate; use judiciously.) Most of the subcomponents in the xml component are related to jaxp. xml jax-ws jaxb javax.xml.parsers (JAXP) javax.xml.stream (JAXP) javax.xml.transform (JAXP) javax.xml.validation (JAXP) javax.xml.xpath (JAXP) jaxp (JAXP) org.w3c.dom (JAXP) org.xml.sax (JAXP) For OpenJDK, most JVM-related bugs are connected to the HotSpot Java virtual machine. hotspot (See hotspot-dev.) build compiler (See hotspot-compiler-dev.) gc (garbage collection, see hotspot-gc-dev.) jfr (Java Flight Recorder) jni (Java Native Interface) jvmti (JVM Tool Interface) mvm (Multi-Tasking Virtual Machine) runtime (See hotspot-runtime-dev.) svc (Servicability) test core-svc (See serviceability-dev.) debugger java.lang.instrument java.lang.management javax.management tools The full JDK bug database contains entries related to legacy virtual machines that predate HotSpot as well as retired APIs. vm-legacy jit (Sun Exact VM) jit_symantec (Symantec VM, before Exact VM) jvmdi (JVM Debug Interface ) jvmpi (JVM Profiler Interface ) runtime (Exact VM Runtime) Notable command line tools in the $JDK/bin directory have corresponding subcomponents. tools appletviewer apt (See compiler-dev.) hprof jar javac (See compiler-dev.) javadoc(tool) (See compiler-dev.) javah (See compiler-dev.) javap (See compiler-dev.) jconsole launcher updaters (Timezone updaters, etc.) visualvm Some aspects of JDK infrastructure directly affect JDK Hg repositories, but other do not. infrastructure build (See build-dev and build-infra-dev.) licensing (Covers updates to the third party readme, licenses, and similar files.) release_eng (Release engineering) staging (Staging of web pages related to JDK releases.) The specification subcomponent encompasses the formal language and virtual machine specifications. specification language (The Java Language Specification) vm (The Java Virtual Machine Specification) The code for the deploy and install areas is not currently included in OpenJDK. deploy deployment_toolkit plugin webstart install auto_update install servicetags In the JDK, there are a number of cross-cutting concerns whose organization is essentially orthogonal to other areas. Since these areas generally have dedicated teams working on them, it is easier to find bugs of interest if these bugs are grouped first by their cross-cutting component rather than by the affected technology. docs doclet guides hotspot release_notes tools tutorial embedded build hotspot libraries globalization locale-data translation performance hotspot libraries The list of subcomponents will no doubt grow over time, but my inclination is to resist that growth since the addition of each subcomponent makes the system as a whole more complicated and harder to use. When the system gets closer to being externalized, I plan to post more blog entries describing recommended use of various custom fields in the JDK project.

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  • Any reliable polygon normal calculation code?

    - by Jenko
    Do you have any reliable face normal calculation code? I'm using this but it fails when faces are 90 degrees upright or similar. // the normal point var x:Number = 0; var y:Number = 0; var z:Number = 0; // if is a triangle with 3 points if (points.length == 3) { // read vertices of triangle var Ax:Number, Bx:Number, Cx:Number; var Ay:Number, By:Number, Cy:Number; var Az:Number, Bz:Number, Cz:Number; Ax = points[0].x; Bx = points[1].x; Cx = points[2].x; Ay = points[0].y; By = points[1].y; Cy = points[2].y; Az = points[0].z; Bz = points[1].z; Cz = points[2].z; // calculate normal of a triangle x = (By - Ay) * (Cz - Az) - (Bz - Az) * (Cy - Ay); y = (Bz - Az) * (Cx - Ax) - (Bx - Ax) * (Cz - Az); z = (Bx - Ax) * (Cy - Ay) - (By - Ay) * (Cx - Ax); // if is a polygon with 4+ points }else if (points.length > 3){ // calculate normal of a polygon using all points var n:int = points.length; x = 0; y = 0; z = 0 // ensure all points above 0 var minx:Number = 0, miny:Number = 0, minz:Number = 0; for (var p:int = 0, pl:int = points.length; p < pl; p++) { var po:_Point3D = points[p] = points[p].clone(); if (po.x < minx) { minx = po.x; } if (po.y < miny) { miny = po.y; } if (po.z < minz) { minz = po.z; } } if (minx > 0 || miny > 0 || minz > 0){ for (p = 0; p < pl; p++) { po = points[p]; po.x -= minx; po.y -= miny; po.z -= minz; } } var cur:int = 1, prev:int = 0, next:int = 2; for (var i:int = 1; i <= n; i++) { // using Newell method x += points[cur].y * (points[next].z - points[prev].z); y += points[cur].z * (points[next].x - points[prev].x); z += points[cur].x * (points[next].y - points[prev].y); cur = (cur+1) % n; next = (next+1) % n; prev = (prev+1) % n; } } // length of the normal var length:Number = Math.sqrt(x * x + y * y + z * z); // if area is 0 if (length == 0) { return null; }else{ // turn large values into a unit vector x = x / length; y = y / length; z = z / length; }

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  • Building ATLAS (and later Octave w/ ATLAS)

    - by David Parks
    I'm trying to set up ATLAS (so I can later compile octave with ATLAS support). If I'm correct, I still need to build this manually due to the environment specific optimizations. I do see a package for ATLAS, but it looks like it's using the cross platform generic build options (e.g. "it'll be slow"). So, running the configure script as described in the docs seems to go poorly. As a java developer I never do well at making heads or tails of errors in these build processes. Am I missing dependencies (if so is there any documentation on what I need)? allusers@vbubuntu:~/Downloads/atlas3.10.1/build_vbubuntu$ ../configure -b 64 -D c -DPentiumCPS=3000 --with-netlib-lapack-tarfile=/home/allusers/Downloads/lapack-3.5.0.tgz make: `xconfig' is up to date. ./xconfig -d s /home/allusers/Downloads/atlas3.10.1/build_vbubuntu/../ -d b /home/allusers/Downloads/atlas3.10.1/build_vbubuntu -b 64 -D c -DPentiumCPS=3000 -Si lapackref 1 OS configured as Linux (1) Assembly configured as GAS_x8664 (2) Vector ISA Extension configured as SSE3 (6,448) ERROR: enum fam=3, chip=2, mach=0 make[3]: *** [atlas_run] Error 44 make[2]: *** [IRunArchInfo_x86] Error 2 Architecture configured as Corei1 (25) ERROR: enum fam=3, chip=2, mach=0 make[3]: *** [atlas_run] Error 44 make[2]: *** [IRunArchInfo_x86] Error 2 Clock rate configured as 2350Mhz ERROR: enum fam=3, chip=2, mach=0 make[3]: *** [atlas_run] Error 44 make[2]: *** [IRunArchInfo_x86] Error 2 Maximum number of threads configured as 4 Parallel make command configured as '$(MAKE) -j 4' ERROR: enum fam=3, chip=2, mach=0 make[3]: *** [atlas_run] Error 44 make[2]: *** [IRunArchInfo_x86] Error 2 Cannot detect CPU throttling. rm -f config1.out make atlas_run atldir=/home/allusers/Downloads/atlas3.10.1/build_vbubuntu exe=xprobe_comp redir=config1.out \ args="-v 0 -o atlconf.txt -O 1 -A 25 -Si nof77 0 -V 448 -b 64 -d b /home/allusers/Downloads/atlas3.10.1/build_vbubuntu" make[1]: Entering directory `/home/allusers/Downloads/atlas3.10.1/build_vbubuntu' cd /home/allusers/Downloads/atlas3.10.1/build_vbubuntu ; ./xprobe_comp -v 0 -o atlconf.txt -O 1 -A 25 -Si nof77 0 -V 448 -b 64 -d b /home/allusers/Downloads/atlas3.10.1/build_vbubuntu > config1.out make[2]: gfortran: Command not found make[2]: *** [IRunF77Comp] Error 127 make[2]: g77: Command not found make[2]: *** [IRunF77Comp] Error 127 make[2]: f77: Command not found make[2]: *** [IRunF77Comp] Error 127 Unable to find usable compiler for F77; abortingMake sure compilers are in your path, and specify good compilers to configure (see INSTALL.txt or 'configure --help' for details)make[1]: *** [atlas_run] Error 8 make[1]: Leaving directory `/home/allusers/Downloads/atlas3.10.1/build_vbubuntu' make: *** [IRun_comp] Error 2 ERROR 512 IN SYSCMND: 'make IRun_comp args="-v 0 -o atlconf.txt -O 1 -A 25 -Si nof77 0 -V 448 -b 64"' mkdir src bin tune interfaces mkdir: cannot create directory ‘src’: File exists mkdir: cannot create directory ‘bin’: File exists mkdir: cannot create directory ‘tune’: File exists mkdir: cannot create directory ‘interfaces’: File exists make: *** [make_subdirs] Error 1 make -f Make.top startup make[1]: Entering directory `/home/allusers/Downloads/atlas3.10.1/build_vbubuntu' Make.top:1: Make.inc: No such file or directory Make.top:325: warning: overriding commands for target `/AtlasTest' Make.top:76: warning: ignoring old commands for target `/AtlasTest' make[1]: *** No rule to make target `Make.inc'. Stop. make[1]: Leaving directory `/home/allusers/Downloads/atlas3.10.1/build_vbubuntu' make: *** [startup] Error 2 mv: cannot move ‘lapack-3.5.0’ to ‘../reference/lapack-3.5.0’: Directory not empty mv: cannot stat ‘lib/Makefile’: No such file or directory ../configure: 450: ../configure: cannot create lib/Makefile: Directory nonexistent ../configure: 451: ../configure: cannot create lib/Makefile: Directory nonexistent ../configure: 452: ../configure: cannot create lib/Makefile: Directory nonexistent ../configure: 453: ../configure: cannot create lib/Makefile: Directory nonexistent ../configure: 509: ../configure: cannot create lib/Makefile: Directory nonexistent DONE configure

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  • Move a sphere along the swipe?

    - by gameOne
    I am trying to get a sphere curl based on the swipe. I know this has been asked many times, but still it's yearning to be answered. I have managed to add force on the direction of the swipe and it works near perfect. I also have all the swipe positions stored in a list. Now I would like to know how can the curl be achieved. I believe the the curve in the swipe can be calculated by the Vector dot product If theta is 0, then there is no need to add the swipe. If it is not, then add the curl. Maybe this condition is redundant if I managed to find how to curl the sphere along the swipe position The code that adds the force to sphere based on the swipe direction is as below: using UnityEngine; using System.Collections; using System.Collections.Generic; public class SwipeControl : MonoBehaviour { //First establish some variables private Vector3 fp; //First finger position private Vector3 lp; //Last finger position private Vector3 ip; //some intermediate finger position private float dragDistance; //Distance needed for a swipe to register public float power; private Vector3 footballPos; private bool canShoot = true; private float factor = 40f; private List<Vector3> touchPositions = new List<Vector3>(); void Start(){ dragDistance = Screen.height*20/100; Physics.gravity = new Vector3(0, -20, 0); footballPos = transform.position; } // Update is called once per frame void Update() { //Examine the touch inputs foreach (Touch touch in Input.touches) { /*if (touch.phase == TouchPhase.Began) { fp = touch.position; lp = touch.position; }*/ if (touch.phase == TouchPhase.Moved) { touchPositions.Add(touch.position); } if (touch.phase == TouchPhase.Ended) { fp = touchPositions[0]; lp = touchPositions[touchPositions.Count-1]; ip = touchPositions[touchPositions.Count/2]; //First check if it's actually a drag if (Mathf.Abs(lp.x - fp.x) > dragDistance || Mathf.Abs(lp.y - fp.y) > dragDistance) { //It's a drag //Now check what direction the drag was //First check which axis if (Mathf.Abs(lp.x - fp.x) > Mathf.Abs(lp.y - fp.y)) { //If the horizontal movement is greater than the vertical movement... if ((lp.x>fp.x) && canShoot) //If the movement was to the right) { //Right move float x = (lp.x - fp.x) / Screen.height * factor; rigidbody.AddForce((new Vector3(x,10,16))*power); Debug.Log("right "+(lp.x-fp.x));//MOVE RIGHT CODE HERE canShoot = false; //rigidbody.AddForce((new Vector3((lp.x-fp.x)/30,10,16))*power); StartCoroutine(ReturnBall()); } else { //Left move float x = (lp.x - fp.x) / Screen.height * factor; rigidbody.AddForce((new Vector3(x,10,16))*power); Debug.Log("left "+(lp.x-fp.x));//MOVE LEFT CODE HERE canShoot = false; //rigidbody.AddForce(new Vector3((lp.x-fp.x)/30,10,16)*power); StartCoroutine(ReturnBall()); } } else { //the vertical movement is greater than the horizontal movement if (lp.y>fp.y) //If the movement was up { //Up move float y = (lp.y-fp.y)/Screen.height*factor; float x = (lp.x - fp.x) / Screen.height * factor; rigidbody.AddForce((new Vector3(x,y,16))*power); Debug.Log("up "+(lp.x-fp.x));//MOVE UP CODE HERE canShoot = false; //rigidbody.AddForce(new Vector3((lp.x-fp.x)/30,10,16)*power); StartCoroutine(ReturnBall()); } else { //Down move Debug.Log("down "+lp+" "+fp);//MOVE DOWN CODE HERE } } } else { //It's a tap Debug.Log("none");//TAP CODE HERE } } } } IEnumerator ReturnBall() { yield return new WaitForSeconds(5.0f); rigidbody.velocity = Vector3.zero; rigidbody.angularVelocity = Vector3.zero; transform.position = footballPos; canShoot =true; isKicked = false; } }

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  • Polite busy-waiting with WRPAUSE on SPARC

    - by Dave
    Unbounded busy-waiting is an poor idea for user-space code, so we typically use spin-then-block strategies when, say, waiting for a lock to be released or some other event. If we're going to spin, even briefly, then we'd prefer to do so in a manner that minimizes performance degradation for other sibling logical processors ("strands") that share compute resources. We want to spin politely and refrain from impeding the progress and performance of other threads — ostensibly doing useful work and making progress — that run on the same core. On a SPARC T4, for instance, 8 strands will share a core, and that core has its own L1 cache and 2 pipelines. On x86 we have the PAUSE instruction, which, naively, can be thought of as a hardware "yield" operator which temporarily surrenders compute resources to threads on sibling strands. Of course this helps avoid intra-core performance interference. On the SPARC T2 our preferred busy-waiting idiom was "RD %CCR,%G0" which is a high-latency no-nop. The T4 provides a dedicated and extremely useful WRPAUSE instruction. The processor architecture manuals are the authoritative source, but briefly, WRPAUSE writes a cycle count into the the PAUSE register, which is ASR27. Barring interrupts, the processor then delays for the requested period. There's no need for the operating system to save the PAUSE register over context switches as it always resets to 0 on traps. Digressing briefly, if you use unbounded spinning then ultimately the kernel will preempt and deschedule your thread if there are other ready threads than are starving. But by using a spin-then-block strategy we can allow other ready threads to run without resorting to involuntary time-slicing, which operates on a long-ish time scale. Generally, that makes your application more responsive. In addition, by blocking voluntarily we give the operating system far more latitude regarding power management. Finally, I should note that while we have OS-level facilities like sched_yield() at our disposal, yielding almost never does what you'd want or naively expect. Returning to WRPAUSE, it's natural to ask how well it works. To help answer that question I wrote a very simple C/pthreads benchmark that launches 8 concurrent threads and binds those threads to processors 0..7. The processors are numbered geographically on the T4, so those threads will all be running on just one core. Unlike the SPARC T2, where logical CPUs 0,1,2 and 3 were assigned to the first pipeline, and CPUs 4,5,6 and 7 were assigned to the 2nd, there's no fixed mapping between CPUs and pipelines in the T4. And in some circumstances when the other 7 logical processors are idling quietly, it's possible for the remaining logical processor to leverage both pipelines. Some number T of the threads will iterate in a tight loop advancing a simple Marsaglia xor-shift pseudo-random number generator. T is a command-line argument. The main thread loops, reporting the aggregate number of PRNG steps performed collectively by those T threads in the last 10 second measurement interval. The other threads (there are 8-T of these) run in a loop busy-waiting concurrently with the T threads. We vary T between 1 and 8 threads, and report on various busy-waiting idioms. The values in the table are the aggregate number of PRNG steps completed by the set of T threads. The unit is millions of iterations per 10 seconds. For the "PRNG step" busy-waiting mode, the busy-waiting threads execute exactly the same code as the T worker threads. We can easily compute the average rate of progress for individual worker threads by dividing the aggregate score by the number of worker threads T. I should note that the PRNG steps are extremely cycle-heavy and access almost no memory, so arguably this microbenchmark is not as representative of "normal" code as it could be. And for the purposes of comparison I included a row in the table that reflects a waiting policy where the waiting threads call poll(NULL,0,1000) and block in the kernel. Obviously this isn't busy-waiting, but the data is interesting for reference. _table { border:2px black dotted; margin: auto; width: auto; } _tr { border: 2px red dashed; } _td { border: 1px green solid; } _table { border:2px black dotted; margin: auto; width: auto; } _tr { border: 2px red dashed; } td { background-color : #E0E0E0 ; text-align : right ; } th { text-align : left ; } td { background-color : #E0E0E0 ; text-align : right ; } th { text-align : left ; } Aggregate progress T = #worker threads Wait Mechanism for 8-T threadsT=1T=2T=3T=4T=5T=6T=7T=8 Park thread in poll() 32653347334833483348334833483348 no-op 415 831 124316482060249729303349 RD %ccr,%g0 "pause" 14262429269228623013316232553349 PRNG step 412 829 124616702092251029303348 WRPause(8000) 32443361333133483349334833483348 WRPause(4000) 32153308331533223347334833473348 WRPause(1000) 30853199322432513310334833483348 WRPause(500) 29173070315032223270330933483348 WRPause(250) 26942864294930773205338833483348 WRPause(100) 21552469262227902911321433303348

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  • Antenna Aligner Part 7: Connecting the dots

    - by Chris George
    The app is basically ready, so I eagerly started to sort out creating the application entry in iTunes Connect. It's mostly intuitive actually, although I did have to create yet another icon for iTunes sized 512x512 pixels, damn lucky I did the original graphics as vector! It took me longer to write the application description than anything else, I'm so not a tech author! I didn't like the way you have to 'make up' an SKU (Stock Keeping Unit) number. I have to do some googling to find out that it really doesn't matter what it is! It should be more obvious what to do from the actual website itself. That aside, the rest of it was actually fairly straightforward. As well as the details of the application, iPhone and iPad screenshots were also required. This posed somewhat of a problem. The iPhone ones were easy (as I have one!), but I do not (yet) own an iPad . So I thought I'd leave the iPad screenshots out for now. Once the application details were sorted, I moved onto the rights and pricing. At the start of the project I had made the decision that I wouldn't charge any more than the lowest amount £0.59. I believe there is a market for this, but as my first foray into app development I didn't want to take the mick. I did realise, however, that I had built my app with a developer certificate and provisioning profile. This was fairly quickly corrected, and again Nomad made this very easy to switch over to the distribution certificate and provisioning profile. With a sense of excitement I cracked open iTunes connect and clicked the upload button ... ...slight snag... . when the Nomad project was started, Apple allowed uploads of these binaries via iTunes Connect. But this is no longer possible, the only upload path is via the Application Loader available from the Apple Developer program. This itself has one limitation, it only runs on a mac! D'OH!!!  Actually my language was somewhat more colourful when this fact came to light. After picking my laptop up off the floor and putting it back together... ok only joking, but I did nearly throw it out of frustration!... I started to consider the options; I briefly entertained the idea of buying a cheap mac from ebay... no, that defeats the whole object of what I'm doing, plus my wife wouldn't be impressed there are some guys out there in the interweb who will upload your app for a small fee...but I don't really like the idea of giving some faceless email address my apple developer login details, as well as my app binary! find some willing friend with a mac who would kindly let me use it... obviously this is the only sensible option. In the meantime, I informed the Nomad team about this slight 'issue' and they are currently investigating possible solutions...

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  • You Probably Already Have a “Private Cloud”

    - by BuckWoody
    I’ve mentioned before that I’m not a fan of the word “Cloud”. It’s too marketing-oriented, gimmicky and non-specific. A better definition (in many cases) is “Distributed Computing”. That means that some or all of the computing functions are handled somewhere other than under your specific control. But there is a current use of the word “Cloud” that does not necessarily mean that the computing is done somewhere else. In fact, it’s a vector of Cloud Computing that can better be termed “Utility Computing”. This has to do with the provisioning of a computing resource. That means the setup, configuration, management, balancing and so on that is needed so that a user – which might actually be a developer – can do some computing work. To that person, the resource is just “there” and works like they expect, like the phone system or any other utility. The interesting thing is, you can do this yourself. In fact, you probably already have been, or are now. It’s got a cool new trendy term – “Private Cloud”, but the fact is, if you have your setup automated, the HA and DR handled, balancing and performance tuning done, and a process wrapped around it all, you can call yourself a “Cloud Provider”. A good example here is your E-Mail system. your users – pretty much your whole company – just logs into e-mail and expects it to work. To them, you are the “Cloud” provider. On your side, the more you automate and provision the system, the more you act like a Cloud Provider. Another example is a database server. In this case, the “end user” is usually the development team, or perhaps your SharePoint group and so on. The data professionals configure, monitor, tune and balance the system all the time. The more this is automated, the more you’re acting like a Cloud Provider. Lots of companies help you do this in your own data centers, from VMWare to IBM and many others. Microsoft's offering in this is based around System Center – they have a “cloud in a box” provisioning system that’s actually pretty slick. The most difficult part of operating a Private Cloud is probably the scale factor. In the case of Windows and SQL Azure, we handle this in multiple ways – and we're happy to share how we do it. It’s not magic, and the algorithms for balancing (like the one we started with called Paxos) are well known. The key is the knowledge, infrastructure and people. Sure, you can do this yourself, and in many cases such as top-secret or private systems, you probably should. But there are times where you should evaluate using Azure or other vendors, or even multiple vendors to spread your risk. All of this should be based on client need, not on what you know how to do already. So congrats on your new role as a “Cloud Provider”. If you have an E-mail system or a database platform, you can just put that right on your resume.

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  • Subterranean IL: The ThreadLocal type

    - by Simon Cooper
    I came across ThreadLocal<T> while I was researching ConcurrentBag. To look at it, it doesn't really make much sense. What's all those extra Cn classes doing in there? Why is there a GenericHolder<T,U,V,W> class? What's going on? However, digging deeper, it's a rather ingenious solution to a tricky problem. Thread statics Declaring that a variable is thread static, that is, values assigned and read from the field is specific to the thread doing the reading, is quite easy in .NET: [ThreadStatic] private static string s_ThreadStaticField; ThreadStaticAttribute is not a pseudo-custom attribute; it is compiled as a normal attribute, but the CLR has in-built magic, activated by that attribute, to redirect accesses to the field based on the executing thread's identity. TheadStaticAttribute provides a simple solution when you want to use a single field as thread-static. What if you want to create an arbitary number of thread static variables at runtime? Thread-static fields can only be declared, and are fixed, at compile time. Prior to .NET 4, you only had one solution - thread local data slots. This is a lesser-known function of Thread that has existed since .NET 1.1: LocalDataStoreSlot threadSlot = Thread.AllocateNamedDataSlot("slot1"); string value = "foo"; Thread.SetData(threadSlot, value); string gettedValue = (string)Thread.GetData(threadSlot); Each instance of LocalStoreDataSlot mediates access to a single slot, and each slot acts like a separate thread-static field. As you can see, using thread data slots is quite cumbersome. You need to keep track of LocalDataStoreSlot objects, it's not obvious how instances of LocalDataStoreSlot correspond to individual thread-static variables, and it's not type safe. It's also relatively slow and complicated; the internal implementation consists of a whole series of classes hanging off a single thread-static field in Thread itself, using various arrays, lists, and locks for synchronization. ThreadLocal<T> is far simpler and easier to use. ThreadLocal ThreadLocal provides an abstraction around thread-static fields that allows it to be used just like any other class; it can be used as a replacement for a thread-static field, it can be used in a List<ThreadLocal<T>>, you can create as many as you need at runtime. So what does it do? It can't just have an instance-specific thread-static field, because thread-static fields have to be declared as static, and so shared between all instances of the declaring type. There's something else going on here. The values stored in instances of ThreadLocal<T> are stored in instantiations of the GenericHolder<T,U,V,W> class, which contains a single ThreadStatic field (s_value) to store the actual value. This class is then instantiated with various combinations of the Cn types for generic arguments. In .NET, each separate instantiation of a generic type has its own static state. For example, GenericHolder<int,C0,C1,C2> has a completely separate s_value field to GenericHolder<int,C1,C14,C1>. This feature is (ab)used by ThreadLocal to emulate instance thread-static fields. Every time an instance of ThreadLocal is constructed, it is assigned a unique number from the static s_currentTypeId field using Interlocked.Increment, in the FindNextTypeIndex method. The hexadecimal representation of that number then defines the specific Cn types that instantiates the GenericHolder class. That instantiation is therefore 'owned' by that instance of ThreadLocal. This gives each instance of ThreadLocal its own ThreadStatic field through a specific unique instantiation of the GenericHolder class. Although GenericHolder has four type variables, the first one is always instantiated to the type stored in the ThreadLocal<T>. This gives three free type variables, each of which can be instantiated to one of 16 types (C0 to C15). This puts an upper limit of 4096 (163) on the number of ThreadLocal<T> instances that can be created for each value of T. That is, there can be a maximum of 4096 instances of ThreadLocal<string>, and separately a maximum of 4096 instances of ThreadLocal<object>, etc. However, there is an upper limit of 16384 enforced on the total number of ThreadLocal instances in the AppDomain. This is to stop too much memory being used by thousands of instantiations of GenericHolder<T,U,V,W>, as once a type is loaded into an AppDomain it cannot be unloaded, and will continue to sit there taking up memory until the AppDomain is unloaded. The total number of ThreadLocal instances created is tracked by the ThreadLocalGlobalCounter class. So what happens when either limit is reached? Firstly, to try and stop this limit being reached, it recycles GenericHolder type indexes of ThreadLocal instances that get disposed using the s_availableIndices concurrent stack. This allows GenericHolder instantiations of disposed ThreadLocal instances to be re-used. But if there aren't any available instantiations, then ThreadLocal falls back on a standard thread local slot using TLSHolder. This makes it very important to dispose of your ThreadLocal instances if you'll be using lots of them, so the type instantiations can be recycled. The previous way of creating arbitary thread-static variables, thread data slots, was slow, clunky, and hard to use. In comparison, ThreadLocal can be used just like any other type, and each instance appears from the outside to be a non-static thread-static variable. It does this by using the CLR type system to assign each instance of ThreadLocal its own instantiated type containing a thread-static field, and so delegating a lot of the bookkeeping that thread data slots had to do to the CLR type system itself! That's a very clever use of the CLR type system.

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  • Antenna Aligner Part 7: Connecting the dots

    - by Chris George
    The app is basically ready, so I eagerly started to sort out creating the application entry in iTunes Connect. It's mostly intuitive actually, although I did have to create yet another icon for iTunes sized 512x512 pixels, damn lucky I did the original graphics as vector! It took me longer to write the application description than anything else, I'm so not a tech author! I didn't like the way you have to 'make up' an SKU (Stock Keeping Unit) number. I have to do some googling to find out that it really doesn't matter what it is! It should be more obvious what to do from the actual website itself. That aside, the rest of it was actually fairly straightforward. As well as the details of the application, iPhone and iPad screenshots were also required. This posed somewhat of a problem. The iPhone ones were easy (as I have one!), but I do not (yet) own an iPad . So I thought I'd leave the iPad screenshots out for now. Once the application details were sorted, I moved onto the rights and pricing. At the start of the project I had made the decision that I wouldn't charge any more than the lowest amount £0.59. I believe there is a market for this, but as my first foray into app development I didn't want to take the mick. I did realise, however, that I had built my app with a developer certificate and provisioning profile. This was fairly quickly corrected, and again Nomad made this very easy to switch over to the distribution certificate and provisioning profile. With a sense of excitement I cracked open iTunes connect and clicked the upload button ... ...slight snag... . when the Nomad project was started, Apple allowed uploads of these binaries via iTunes Connect. But this is no longer possible, the only upload path is via the Application Loader available from the Apple Developer program. This itself has one limitation, it only runs on a mac! D'OH!!!  Actually my language was somewhat more colourful when this fact came to light. After picking my laptop up off the floor and putting it back together... ok only joking, but I did nearly throw it out of frustration!... I started to consider the options; I briefly entertained the idea of buying a cheap mac from ebay... no, that defeats the whole object of what I'm doing, plus my wife wouldn't be impressed there are some guys out there in the interweb who will upload your app for a small fee...but I don't really like the idea of giving some faceless email address my apple developer login details, as well as my app binary! find some willing friend with a mac who would kindly let me use it... obviously this is the only sensible option. In the meantime, I informed the Nomad team about this slight 'issue' and they are currently investigating possible solutions...

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  • 4 Ways Your Brand Can Jump From the Edge of Space

    - by Mike Stiles
    Can your brand’s social media content captivate the world and make it hold its collective breath? Can you put something on the screen that’s so compelling that your audience can’t look away? Will they want to make sure their friends see it so they can talk about it? If not, you’re probably not with Red Bull. I was impressed with Red Bull’s approach to social content even before Felix Baumgartner’s stunning skydive from the edge of space. And then they did this. According to Visible Measures, videos of the jump scored 50 million views in 4 days. 1,700 clips were generated from both official and organic sources. The live stream was the most watched YouTube Stream of all time (8 million concurrent viewers). The 2nd most watched live stream was…Felix’ first attempt Oct. 9. Are you ready to compete with that? I ask that question because some brands are still out there tying themselves up in knots about whether or not they should tweet. The public’s time and attention are scarce commodities, commodities they value greatly. The competition amongst brands for that time and attention is intense and going up like Felix’s capsule. If you still view your press releases as “content,” you won’t even be counted as being among the competition. Here are 5 lessons learned from Red Bull’s big leap: 1. They have a total understanding of their target market and audience. Not only do they have an understanding of it, they do something about it. They act on it. They fill the majority of their thoughts with what the audience wants. They hunger for wild applause from that audience. They want to do things that embrace the audience’s lifestyle and immerse in it so the target will identify the brand as “one of them.” Takeaway: BE your target market. 2. They deliver content that strikes the audience right where they emotionally live. If you want your content to have impact, you have to make your audience’s heart race, or make them tear up, or make them laugh. Label them “data points” all you want, but humans are emotional creatures. No message connects that’s not carried in on an emotion. Takeaway: You’re on the inside. If your content doesn’t make you say “wow,” it’s unlikely it will register with fans. 3. They put aside old school marketing and don’t let their content be degraded into a commercial. Their execs seem to understand the value in keeping a lid on the hard sell. So many brands just can’t bring themselves to disconnect advertising and social content. The result is, otherwise decent content gets contaminated with a desperation the viewer can smell a mile away. Think the Baumgartner skydive didn’t do Red Bull any good since he wasn’t drinking one on the way down while singing a jingle? Analysis company Taykey discovered that at the peak of the skydive buzz, about 1% of all online conversation was about the jump. Mentions of Red Bull constituted 1/3 of 1% of all Internet activity. Views of other Red Bull videos also shot up. Takeaway: Chill out with the ads. Your brand will get full credit for entertaining/informing fans in a relevant way, provided you do it. 4. They don’t hesitate to ask, “What can we do next”? Most corporate cultures are a virtual training facility for “we can’t do that.” Few are encouraged to innovate or think big, if think at all. Thinking big involves faith, and work. It means freedom and letting employees run a little wild with their ideas. There will always be the opportunity to let fear of everything that moves creep in and kill grand visions dead in their tracks. Experimenting must be allowed. Failure must be allowed. Red Bull didn’t think big. They thought mega. They tried to outdo themselves. Felix could have gone ahead and jumped halfway up, thinking, “This is still relatively high up. Good enough.” But that wouldn’t have left us breathless. Takeaway: Go for it. Jump. In putting up social properties and gathering fans of your brand, you’ve basically invited people to a party. A good host doesn’t just set out warm beer and stale chips because that’s inexpensive and easy. Be on the lookout for ways to make your guests walk away saying, “That was epic.”

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  • AI to move custom-shaped spaceships (shape affecting movement behaviour)

    - by kaoD
    I'm designing a networked turn based 3D-6DOF space fleet combat strategy game which relies heavily on ship customization. Let me explain the game a bit, since you need to know a bit about it to set the question. What I aim for is the ability to create your own fleet of ships with custom shapes and attached modules (propellers, tractor beams...) which would give advantages and disadvantages to each ship, so you have lots of different fleet distributions. E.g., long ship with two propellers at the side would let the ship spin around that plane easily, bigger ships would move slowly unless you place lots of propellers at the back (therefore spending more "construction" points and energy when moving, and it will only move fast towards that direction.) I plan to balance all the game around this feature. The game would revolve around two phases: orders and combat phase. During the orders phase, you command the different ships. When all players finish the order phase, the combat phase begins and the ship orders get resolved in real-time for some time, then the action pauses and there's a new orders phase. The problem comes when I think about player input. To move a ship, you need to turn on or off different propellers if you want to steer, travel forward, brake, rotate in place... These propellers don't have to work at their whole power, so you can achieve more movement combinations with less propellers. I think this approach is a bit boring. The player doesn't want to fiddle with motors or anything, you just want to MOVE and KILL. The way I intend the player to give orders to these ships is by a destination and a rotation, and then the AI would calculate the correct propeller power to achive that movement and rotation. Propulsion doesn't have to be the same throught the entire turn calculation (after the orders have been given) so it would be cool if the ships reacted as they move, adjusting the power of the propellers for their needs dynamically, but it may be too hard to implement and it's not really needed for the game to work. In both cases, how would that AI decide which propellers to activate for the best (or at least not worst) trajectory to be achieved? I though about some approaches: Learning AI: The ship types would learn about their movement by trial and error, adjusting their behaviour with more uses, and finally becoming "smart". I don't want to get involved THAT far in AI coding, and I think it can be frustrating for the player (even if you can let it learn without playing.) Pre-calculated timestep movement: Upon ship creation, ALL possible movements are calculated for each propeller configuration and power for a given delta-time. Memory intensive, ugly, bad. Pre-calculated trajectories: The same as above but not for each delta-time but the whole trajectory, which would then be fitted as much as possible. Requires a fixed propeller configuration for the whole combat phase and is still memory intensive, ugly and bad. Continuous brute forcing: The AI continously checks ALL possible propeller configurations throughout the entire combat phase, precalculates a few time steps and decides which is the best one based on that. Con: what's good now might not be that good later, and it's too CPU intensive, ugly, and bad too. Single brute forcing: Same as above, but only brute forcing at the beginning of the simulation, so it needs constant propeller configuration throughout the entire combat phase. Coninuous angle check: This is not a full movement method, but maybe a way to discard "stupid" propeller configurations. Given the current propeller's normal vector and the final one, you can approximate the power needed for the propeller based on the angle. You must do this continuously throughout the whole combat phase. I figured this one out recently so I didn't put in too much thought. A priori, it has the "what's good now might not be that good later" drawback too, and it doesn't care about the other propellers which may act together to make a better propelling configuration. I'm really stuck here. Any ideas?

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  • How can a developer realize the full value of his work [closed]

    - by Jubbat
    I, honestly, don't want to work as a developer in a company anymore after all I have seen. I want to continue developing software, yes, but not in the way I see it all around me. And I'm in London, a city that congregates lots of great developers from the whole world, so it shouldn't be a problem of location. So, what are my concerns? First of all, best case scenario: you are paying managers salary out of yours. You are consistently underpaid by making up for the average manager negative net return plus his whole salary. Typical scenario. I am a reasonably good developer with common sense who cares for readable code with attention to basic principles. I have found way too often, overconfident and arrogant developers with a severe lack of common sense. Personally, I don't want to follow TDD or Agile practices like all the cool kids nowadays. I would read about them, form my own opinion and take what I feel is useful, but don't follow it sheepishly. I want to work with people who understand that you have to design good interfaces, you absolutely have to document your code, that readability is at the top of your priorities. Also people who don't have a cargo cult mentality too. For instance, the same person who asked me about design patterns in a job interview, later told me that something like a List of Map of Vector of Map of Set (in Java) is very readable. Why would someone ask me about design patterns if they can't even grasp encapsulation? These kind of things are the norm. I've seen many examples. I've seen worse than that too, from very well paid senior devs, by the way. Every second that you spend working with people with such lack of common sense and clear thinking, you are effectively losing money by being terribly inefficient with your time. Yet, with all these inefficiencies, the average developer earns a high salary. So I tried working on my own then, although I don't like the idea. I prefer healthy exchange of opinions and ideas and task division. I then did a bit of online freelancing for a while but I think working in a sweatshop might be more enjoyable. Also, I studied computer engineering and you are in an environment in which your client will presume you don't have any formal education because there is no way to prove it. Again, you are undervalued. You could try building a product, yes. But, of course, luck is a big factor. I wonder if there is a way to work in something you can do well, software development, and be valued for the quality of your work and be paid accordingly, and where you and only you get fairly paid for the value you generate. I know that what I have written seems somehow unlikely but I strongly feel this way. Hopefully someone will understand me and has already figured this out. I don't think I'm alone in this kind of feeling.

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  • Improving the efficiency of frustum culling

    - by DeadMG
    I've got some code which performs frustum culling. However, this defines the "frustum" way too broadly- when I have ~10 objects on screen, the code returns 42 objects to be rendered. I've tried taking "slices" through the frustum to attempt to increase the accuracy of the technique, but it doesn't seem to have made much impact. I also significantly reduced the far plane, so that the objects are barely at the edge. Here's my code (where size is the size in screen space- the resolution of the client area of the window I'm rendering into). Any suggestions? auto&& size = GetDimensions(); D3DVIEWPORT9 vp = { 0, 0, size.x, size.y, 0, 1 }; D3DCALL(device->SetViewport(&vp)); static const int slices = 10; std::vector<Object*> result; for(int i = 0; i < slices; i++) { D3DXVECTOR3 WorldSpaceFrustrumPoints[8] = { D3DXVECTOR3(0, size.y, static_cast<float>(i) / slices), D3DXVECTOR3(size.x, 0, static_cast<float>(i) / slices), D3DXVECTOR3(size.x, size.y, static_cast<float>(i) / slices), D3DXVECTOR3(0, 0, static_cast<float>(i) / slices), D3DXVECTOR3(0, 0, static_cast<float>(i + 1) / slices), D3DXVECTOR3(size.x, 0, static_cast<float>(i + 1) / slices), D3DXVECTOR3(size.x, size.y, static_cast<float>(i + 1) / slices), D3DXVECTOR3(0, size.y, static_cast<float>(i + 1) / slices) }; D3DXMATRIXA16 Identity; D3DXMatrixIdentity(&Identity); D3DXVec3UnprojectArray( WorldSpaceFrustrumPoints, sizeof(D3DXVECTOR3), WorldSpaceFrustrumPoints, sizeof(D3DXVECTOR3), &vp, &Projection, &View, &Identity, 8 ); Math::AABB Frustrum; auto world_begin = std::begin(WorldSpaceFrustrumPoints); auto world_end = std::end(WorldSpaceFrustrumPoints); auto world_initial = WorldSpaceFrustrumPoints[0]; Frustrum.BottomLeftClosest.x = std::accumulate(world_begin, world_end, world_initial, [](D3DXVECTOR3 lhs, D3DXVECTOR3 rhs) { return lhs.x < rhs.x ? lhs : rhs; }).x; Frustrum.BottomLeftClosest.y = std::accumulate(world_begin, world_end, world_initial, [](D3DXVECTOR3 lhs, D3DXVECTOR3 rhs) { return lhs.y < rhs.y ? lhs : rhs; }).y; Frustrum.BottomLeftClosest.z = std::accumulate(world_begin, world_end, world_initial, [](D3DXVECTOR3 lhs, D3DXVECTOR3 rhs) { return lhs.z < rhs.z ? lhs : rhs; }).z; Frustrum.TopRightFurthest.x = std::accumulate(world_begin, world_end, world_initial, [](D3DXVECTOR3 lhs, D3DXVECTOR3 rhs) { return lhs.x > rhs.x ? lhs : rhs; }).x; Frustrum.TopRightFurthest.y = std::accumulate(world_begin, world_end, world_initial, [](D3DXVECTOR3 lhs, D3DXVECTOR3 rhs) { return lhs.y > rhs.y ? lhs : rhs; }).y; Frustrum.TopRightFurthest.z = std::accumulate(world_begin, world_end, world_initial, [](D3DXVECTOR3 lhs, D3DXVECTOR3 rhs) { return lhs.z > rhs.z ? lhs : rhs; }).z; auto slices_result = ObjectTree.collision(Frustrum); result.insert(result.end(), slices_result.begin(), slices_result.end()); } return result;

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  • concurrency::extent<N> from amp.h

    - by Daniel Moth
    Overview We saw in a previous post how index<N> represents a point in N-dimensional space and in this post we'll see how to define the N-dimensional space itself. With C++ AMP, an N-dimensional space can be specified with the template class extent<N> where you define the size of each dimension. From a look and feel perspective, you'd expect the programmatic interface of a point type and size type to be similar (even though the concepts are different). Indeed, exactly like index<N>, extent<N> is essentially a coordinate vector of N integers ordered from most- to least- significant, BUT each integer represents the size for that dimension (and hence cannot be negative). So, if you read the description of index, you won't be surprised with the below description of extent<N> There is the rank field returning the value of N you passed as the template parameter. You can construct one extent from another (via the copy constructor or the assignment operator), you can construct it by passing an integer array, or via convenience constructor overloads for 1- 2- and 3- dimension extents. Note that the parameterless constructor creates an extent of the specified rank with all bounds initialized to 0. You can access the components of the extent through the subscript operator (passing it an integer). You can perform some arithmetic operations between extent objects through operator overloading, i.e. ==, !=, +=, -=, +, -. There are operator overloads so that you can perform operations between an extent and an integer: -- (pre- and post- decrement), ++ (pre- and post- increment), %=, *=, /=, +=, –= and, finally, there are additional overloads for plus and minus (+,-) between extent<N> and index<N> objects, returning a new extent object as the result. In addition to the usual suspects, extent offers a contains function that tests if an index is within the bounds of the extent (assuming an origin of zero). It also has a size function that returns the total linear size of this extent<N> in units of elements. Example code extent<2> e(3, 4); _ASSERT(e.rank == 2); _ASSERT(e.size() == 3 * 4); e += 3; e[1] += 6; e = e + index<2>(3,-4); _ASSERT(e == extent<2>(9, 9)); _ASSERT( e.contains(index<2>(8, 8))); _ASSERT(!e.contains(index<2>(8, 9))); grid<N> Our upcoming pre-release bits also have a similar type to extent, grid<N>. The way you create a grid is by passing it an extent, e.g. extent<3> e(4,2,6); grid<3> g(e); I am not going to dive deeper into grid, suffice for now to think of grid<N> simply as an alias for the extent<N> object, that you create when you encounter a function that expects a grid object instead of an extent object. Usage The extent class on its own simply defines the size of the N-dimensional space. We'll see in future posts that when you create containers (arrays) and wrappers (array_views) for your data, it is an extent<N> object that you'll need to use to create those (and use an index<N> object to index into them). We'll also see that it is a grid<N> object that you pass to the new parallel_for_each function that I'll cover in the next post. Comments about this post by Daniel Moth welcome at the original blog.

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  • Pantech Link II, Ubuntu and Virtual XP

    - by user85041
    Okay this is my problem. I have a Pantech Link II, dmesg states: [ 896.072037] usb 2-3: new high-speed USB device number 3 using ehci_hcd [ 896.258562] cdc_acm 2-3:1.0: ttyACM0: USB ACM device [ 896.260039] usbcore: registered new interface driver cdc_acm [ 896.260042] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters Have it installed through wine (pc suite and driver) and it doesn't see it. Virtual XP through VMWare Player sees my device, knows it needs a driver. The removable devices says Curitel Pantech USB Device (Maybe Driver). I have PC Suite installed in XP, I install the driver through the executable.. it says problem with installing hardware, and then it disappears. Ubuntu sees it after restart, but if I start XP with that driver installed, it disappears from both and I get these errors in dmesg: [ 1047.760555] /dev/vmmon[2882]: PTSC: initialized at 3093322000 Hz using TSC, TSCs are synchronized. [ 1048.174033] /dev/vmmon[2882]: Monitor IPI vector: 0 [ 1055.293060] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1055.293074] /dev/vmnet: port on hub 8 successfully opened [ 1055.293088] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1055.293094] /dev/vmnet: port on hub 8 successfully opened [ 1072.446305] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1072.446316] /dev/vmnet: port on hub 8 successfully opened [ 1072.446328] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1072.446334] /dev/vmnet: port on hub 8 successfully opened [ 1072.856024] usb 1-1: reset high-speed USB device number 2 using ehci_hcd [ 1079.292024] usb 1-1: reset high-speed USB device number 2 using ehci_hcd [ 1079.732024] usb 1-1: reset high-speed USB device number 2 using ehci_hcd [ 1127.743034] NET: Registered protocol family 39 [ 1127.749320] [3163]: VMCI: IOCTL_VMCI_QUEUEPAIR_ALLOC (cid=1522210225,result=4). [ 1144.104031] usb 2-3: reset high-speed USB device number 3 using ehci_hcd [ 1144.412031] usb 2-3: reset high-speed USB device number 3 using ehci_hcd [ 1155.889976] ehci_hcd 0000:00:13.2: force halt; handshake ffffc90000642024 00004000 00000000 -> -110 [ 1155.889980] ehci_hcd 0000:00:13.2: HC died; cleaning up [ 1155.890008] usb 2-3: USB disconnect, device number 3 [ 1155.890013] usb 2-3: usbfs: usb_submit_urb returned -110 [ 1658.310777] [3163]: VMCI: IOCTL_VMCI_QUEUEPAIR_DETACH (cid=1522210225,result=3). [ 1658.392018] NET: Unregistered protocol family 39 [ 1666.546438] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1666.546450] /dev/vmnet: port on hub 8 successfully opened [ 1666.546462] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1666.546467] /dev/vmnet: port on hub 8 successfully opened [ 1671.431383] uvcvideo: Found UVC 1.00 device USB2.0 Camera (1871:0101) [ 1671.432533] input: USB2.0 Camera as /devices/pci0000:00/0000:00:12.2/usb1/1-1/1-1:1.0/input/input13 lessa@X:~$ dmesg|tail [ 1155.890008] usb 2-3: USB disconnect, device number 3 [ 1155.890013] usb 2-3: usbfs: usb_submit_urb returned -110 [ 1658.310777] [3163]: VMCI: IOCTL_VMCI_QUEUEPAIR_DETACH (cid=1522210225,result=3). [ 1658.392018] NET: Unregistered protocol family 39 [ 1666.546438] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1666.546450] /dev/vmnet: port on hub 8 successfully opened [ 1666.546462] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1666.546467] /dev/vmnet: port on hub 8 successfully opened [ 1671.431383] uvcvideo: Found UVC 1.00 device USB2.0 Camera (1871:0101) [ 1671.432533] input: USB2.0 Camera as /devices/pci0000:00/0000:00:12.2/usb1/1-1/1-1:1.0/input/input13 I have tried uninstalling, and installing manually from the device manager update driver while it's still has the warning sign.. it doesn't see the drivers as valid. No idea how to fix this.. would prefer to not have to go to another computer. I'm not trying to do anything but get the pictures off of it. I have to restart ubuntu, plug in device, for ubuntu to see it correctly again. I am like a month and a half old linux newbie so I have no idea the commands I could use for this, and I don't have a memory card in the phone to mount.

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