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• Date range advanced count calculation in TSQL

  - by cihata87

  I am working on call center project and I have to calculate the call arrivals at the same time between specific time ranges. I have to write a procedure which has parameters StartTime, EndTime and Interval For Example: Start Time: 11:00 End Time: 12:00 Interval: 20 minutes so program should divide the 1-hour time range into 3 parts and each part should count the arrivals which started and finished in this range OR arrivals which started and haven't finished yet Should be like this: 11:00 - 11:20 15 calls at the same time(TimePeaks) 11:20 - 11:40 21 calls ... 11:40 - 12:00 8 calls ... Any suggestions how to calculate them?

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• Finding a integer number after a beginning t=

  - by user2966696

  I have a string like this: 33 00 4b 46 ff ff 03 10 30 t=25562 I am only interested in the five digits at the very end after the t= How can I get this numbers with a regular expression out of it? I tried grep t=..... but I also got all characters including the t= in the beginning, which I would like to drop? After finding that five digit number, I would like to divide this by 1000. So in the above mentioned case the number 25.562. Is this possible with grep and regular expressions? Thanks for your help.

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• Some apps very slow to load on Windows 7, copy & paste very slow.

  - by Mike

  Hello, I searched here and couldn't find a similar issue to mine but apologies if I missed it. I've searched the web and no one else seems to be having the same issue either. I'm running Windows 7 Ultimate 64bit on a pretty high spec. machine (well, apart from the graphics): Asus M4A79T Deluxe AMD Phenom II 965 black edition (quad core, 3.4GHz) 8GB Crucial Ballistix DDR 1333MHz RAM 80GB Intex X25 SSD for OS 500GB mechanical drive for data. ATi Radeon HD 4600 series PCI-e Be Quiet! 850W PSU I think those are all the relevant stats, if you need anything else let me know. I've updated chipset, graphics and various other drivers all to no avail, the problem remains. I have also unplugged and replugged every connection internally and cleaned the RAM edge connectors. The problems: Video LAN (VLC) and CDBurnerXP both take ages to load, I'm talking 30 seconds and 1 minute respectively which is really not right. Copy and paste from Open Office spread sheet into Fire Fox, for example, is really, really slow, I'll have pressed control V 5 or 6 times before it actually happens, if I copy and then wait 5 to 10 seconds or so it'll paste first time so it's definitely some sort of time lag. Command and Conquer - Generals: Zero Hour. When playing it'll run perfectly for about 10 or 20 seconds then it'll just pause for 3 or 4 then run for another 10 or 20 seconds and pause again and so on. I had the Task Manager open on my 2nd monitor whilst playing once and I noticed it was using about 25% of the CPU, pretty stable but when the pause came another task didn't shoot up to 100% like others on the web have been reporting (similar but not the same as my issue, often svchost.exe for them) but dropped to 2 or 3% usage then back up to 25% when it started playing properly again. Very odd! But it gets even odder... I had a BSOD and reboot last week, when it rebooted the problem had completely gone, I could play C&C to my heart's content and both the other apps loaded instantly, copy and paste worked instantly too. I did an AVG update earlier this week which required a reboot, rebooted and the problem's back. I don't think it's AVG related though, I think it was just coincidence that's the app that required a reboot. I think any reboot would have brought the issue back. A number of reboots later and it hasn't gone away again. If any one could make any suggestions as to the likely cause and solution to these issues I'd be most grateful, it's driving me nuts! Thanks, Mike....

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• Dividing web.config into multiple files in asp.net

  - by Jalpesh P. Vadgama

  When you are having different people working on one project remotely you will get some problem with web.config, as everybody was having different version of web.config. So at that time once you check in your web.config with your latest changes the other people have to get latest that web.config and made some specific changes as per their local environment. Most of people who have worked things from remotely has faced that problem. I think most common example would be connection string and app settings changes. For this kind of situation this will be a best solution. We can divide particular section of web.config into the multiple files. For example we could have separate ConnectionStrings.config file for connection strings and AppSettings.config file for app settings file. Most of people does not know that there is attribute called ‘configSource’ where we can  define the path of external config file and it will load that section from that external file. Just like below. <configuration> <appSettings configSource="AppSettings.config"/> <connectionStrings configSource="ConnectionStrings.config"/> </configuration> And you could have your ConnectionStrings.config file like following. <connectionStrings> <add name="DefaultConnection" connectionString="Data Source=(LocalDb)\v11.0;Initial Catalog=aspnet-WebApplication1-20120523114732;Integrated Security=True" providerName="System.Data.SqlClient" /> </connectionStrings> Same way you have another AppSettings.Config file like following. <appSettings> <add key="aspnet:UseTaskFriendlySynchronizationContext" value="true" /> <add key="ValidationSettings:UnobtrusiveValidationMode" value="WebForms" /> </appSettings> That's it. Hope you like this post. Stay tuned for more..

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• Do unit tests sometimes break encapsulation?

  - by user1288851

  I very often hear the following: "If you want to test private methods, you'd better put that in another class and expose it." While sometimes that's the case and we have a hiding concept inside our class, other times you end up with classes that have the same attributes (or, worst, every attribute of one class become a argument on a method in the other class) and exposes functionality that is, in fact, implementation detail. Specially on TDD, when you refactor a class with public methods out of a previous tested class, that class is now part of your interface, but has no tests to it (since you refactored it, and is a implementation detail). Now, I may be not finding an obvious better answer, but if my answer is the "correct", that means that sometimes writting unit tests can break encapsulation, and divide the same responsibility into different classes. A simple example would be testing a setter method when a getter is not actually needed for anything in the real code. Please when aswering don't provide simple answers to specific cases I may have written. Rather, try to explain more of the generic case and theoretical approach. And this is neither language specific. Thanks in advance. EDIT: The answer given by Matthew Flynn was really insightful, but didn't quite answer the question. Altough he made the fair point that you either don't test private methods or extract them because they really are other concern and responsibility (or at least that was what I could understand from his answer), I think there are situations where unit testing private methods is useful. My primary example is when you have a class that has one responsibility but the output (or input) that it gives (takes) is just to complex. For example, a hashing function. There's no good way to break a hashing function apart and mantain cohesion and encapsulation. However, testing a hashing function can be really tough, since you would need to calculate by hand (you can't use code calculation to test code calculation!) the hashing, and test multiple cases where the hash changes. In that way (and this may be a question worth of its own topic) I think private method testing is the best way to handle it. Now, I'm not sure if I should ask another question, or ask it here, but are there any better way to test such complex output (input)? OBS: Please, if you think I should ask another question on that topic, leave a comment. :)

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• Chuck Norris Be Thy Name

  - by Robz / Fervent Coder

  Chuck Norris doesn’t program with a keyboard. He stares the computer down until it does what he wants. All things need a name. We’ve tossed around a bunch of names for the framework of tools we’ve been working on, but one we kept coming back to was Chuck Norris. Why did we choose Chuck Norris? Well Chuck Norris sort of chose us. Everything we talked about, the name kept drawing us closer to it. We couldn’t escape Chuck Norris, no matter how hard we tried. So we gave in. Chuck Norris can divide by zero. What is the Chuck Norris Framework? @drusellers and I have been working on a variety of tools: WarmuP - http://github.com/chucknorris/warmup (Template your entire project/solution and create projects ready to code - From Zero to a Solution with everything in seconds. Your templates, your choices.) UppercuT - http://projectuppercut.org (Build with Conventions - Professional Builds in Moments, Not Days!) | Code also at http://github.com/chucknorris/uppercut DropkicK - http://github.com/chucknorris/dropkick (Deploy Fluently) RoundhousE - http://projectroundhouse.org (Professional Database Management with Versioning) | Code also at http://github.com/chucknorris/roundhouse SidePOP - http://sidepop.googlecode.com (Does your application need to check email?) HeadlocK - http://github.com/chucknorris/headlock (Hash a directory so you can later know if anything has changed) Others – still in concept or vaporware People ask why we choose such violent names for each tool of our framework? At first it was about whipping your code into shape, but after awhile the naming became, “How can we relate this to Chuck Norris?” People also ask why we uppercase the last letter of each name. Well, that’s more about making you ask questions…but there are a few reasons for it. Project managers never ask Chuck Norris for estimations…ever. The class object inherits from Chuck Norris Chuck Norris doesn’t need garbage collection because he doesn’t call .Dispose(), he calls .DropKick() So what are you waiting for? Join the Google group today, download and play with the tools. And lastly, welcome to Chuck Norris. Or should I say Chuck Norris welcomes you…

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• Cocos2d: Changing b2Body x val every frame causes jitter

  - by Joey Green

  So, I have a jumping mechanism similar to what you would see in doodle jump where character jumps and you use the accelerometer to make character change direction left or right. I have a player object with position and a box2d b2Body with position. I'm changing the player X position via the accelerometer and the Y position according to box2d. pseudocode for this is like so -----accelerometer acceleration------ player.position = new X -----world update--------- physicsWorld-step() //this will get me the new Y according to the physics similation //so we keep the bodys Y value but change x to new X according to accelerometer data playerPhysicsBody.position = new pos(player.position.x, keepYval) player.position = playerPhysicsBody.position Now this is simplifying my code, but I'm doing the position conversion back and forth via mult or divide by PTM_. Well, I'm getting a weird jitter effect after I get big jump in acceleration data. So, my questions are: 1) Is this the right approach to have the accelerometer control the x pos and box2d control the y pos and just sync everthing up every frame? 2) Is there some issue with updating a b2body x position every frame? 3) Any idea what might be creating this jitter effect? I've collecting some data while running the game. Pre-body is before I set the x value on the b2Body in my update method after I world-step(). Post of course is afterwards. As you can see there is definitively a pattern. 012-06-19 08:14:13.118 Game[1073:707] pre-body pos 5.518720~24.362963 2012-06-19 08:14:13.120 Game[1073:707] post-body pos 5.060156~24.362963 2012-06-19 08:14:13.131 Game[1073:707] player velocity x: -31.833529 2012-06-19 08:14:13.133 Game[1073:707] delta 0.016669 2012-06-19 08:14:13.135 Game[1073:707] pre-body pos 5.060156~24.689455 2012-06-19 08:14:13.137 Game[1073:707] post-body pos 5.502138~24.689455 2012-06-19 08:14:13.148 Game[1073:707] player velocity x: -31.833529 2012-06-19 08:14:13.150 Game[1073:707] delta 0.016667 2012-06-19 08:14:13.151 Game[1073:707] pre-body pos 5.502138~25.006948 2012-06-19 08:14:13.153 Game[1073:707] post-body pos 5.043575~25.006948 2012-06-19 08:14:13.165 Game[1073:707] player velocity x: -31.833529 2012-06-19 08:14:13.167 Game[1073:707] delta 0.016644 2012-06-19 08:14:13.169 Game[1073:707] pre-body pos 5.043575~25.315441 2012-06-19 08:14:13.170 Game[1073:707] post-body pos 5.485580~25.315441 2012-06-19 08:14:13.180 Game[1073:707] player velocity x: -31.833529 2012-06-19 08:14:13.182 Game[1073:707] delta 0.016895 2012-06-19 08:14:13.185 Game[1073:707] pre-body pos 5.485580~25.614935 2012-06-19 08:14:13.188 Game[1073:707] post-body pos 5.026768~25.614935 2012-06-19 08:14:13.198 Game[1073:707] player velocity x: -31.833529 2012-06-19 08:14:13.199 Game[1073:707] delta 0.016454 2012-06-19 08:14:13.207 Game[1073:707] pre-body pos 5.026768~25.905428 2012-06-19 08:14:13.211 Game[1073:707] post-body pos 5.469213~25.905428 2012-06-19 08:14:13.217 Game[1073:707] acceleration x -0.137421 2012-06-19 08:14:13.223 Game[1073:707] player velocity x: -65.022644 2012-06-19 08:14:13.229 Game[1073:707] delta 0.016603

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• Algorithm for spreading labels in a visually appealing and intuitive way

  - by mac

  Short version Is there a design pattern for distributing vehicle labels in a non-overlapping fashion, placing them as close as possible to the vehicle they refer to? If not, is any of the method I suggest viable? How would you implement this yourself? Extended version In the game I'm writing I have a bird-eye vision of my airborne vehicles. I also have next to each of the vehicles a small label with key-data about the vehicle. This is an actual screenshot: Now, since the vehicles could be flying at different altitudes, their icons could overlap. However I would like to never have their labels overlapping (or a label from vehicle 'A' overlap the icon of vehicle 'B'). Currently, I can detect collisions between sprites and I simply push away the offending label in a direction opposite to the otherwise-overlapped sprite. This works in most situations, but when the airspace get crowded, the label can get pushed very far away from its vehicle, even if there was an alternate "smarter" alternative. For example I get: B - label A -----------label C - label where it would be better (= label closer to the vehicle) to get: B - label label - A C - label EDIT: It also has to be considered that beside the overlapping vehicles case, there might be other configurations in which vehicles'labels could overlap (the ASCII-art examples show for example three very close vehicles in which the label of A would overlap the icon of B and C). I have two ideas on how to improve the present situation, but before spending time implementing them, I thought to turn to the community for advice (after all it seems like a "common enough problem" that a design pattern for it could exist). For what it's worth, here's the two ideas I was thinking to: Slot-isation of label space In this scenario I would divide all the screen into "slots" for the labels. Then, each vehicle would always have its label placed in the closest empty one (empty = no other sprites at that location. Spiralling search From the location of the vehicle on the screen, I would try to place the label at increasing angles and then at increasing radiuses, until a non-overlapping location is found. Something down the line of: try 0°, 10px try 10°, 10px try 20°, 10px ... try 350°, 10px try 0°, 20px try 10°, 20px ...

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• Mathemagics - 3 consecutive number

  - by PointsToShare

  © 2011 By: Dov Trietsch. All rights reserved Three Consecutive numbers When I was young and handsome (OK, OK, just young), my father used to challenge us with riddles and tricks involving Logic, Math and general knowledge. Most of the time, at least after reaching the ripe age of 10, I would see thru his tricks in no time. This one is a bit more subtle. I had to think about it for close to an hour and then when I had the ‘AHA!’ effect, I could not understand why it had taken me so long. So here it is. You select a volunteer from the audience (or a shill, but that would be cheating!) and ask him to select three consecutive numbers, all of them 1 or 2 digits. So {1, 2, 3} would be good, albeit trivial set, as would {8, 9, 10} or {97, 98, 99} but not {99, 99, 100} (why?!). Now, using a calculator – and these days almost every phone has a built in calculator – he is to perform these steps: 1.      Select a single digit 2.      Multiply it by 3 and write it down 3.      Add the 3 consecutive numbers 4.      Add the number from step 2 5.      Multiply the sum by 67 6.      Now tell me the last 2 digits of the result and also the number you wrote down in step 2 I will tell you which numbers you selected. How do I do this? I’ll give you the mechanical answer, but because I like you to have the pleasure of an ‘AHA!’ effect, I will not really explain the ‘why’. So let’s you selected 30, 31, and 32 and also that your 3 multiple was 24, so here is what you get 30 + 31 + 32 = 93 93 + 24 = 117 117 x 67 = 7839, last 2 digits are 39, so you say “the last 2 digits are 39, and the other number is 24.” Now, I divide 24 by 3 getting 8. I subtract 8 from 39 and get 31. I then subtract 1 from this getting 30, and say: “You selected 30, 31, and 32.” This is the ‘how’. I leave the ‘why’ to you! That’s all folks! PS do you really want to know why? Post a feedback below. When 11 people or more will have asked for it, I’ll add a link to the full explanation.

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• Cannot dual Windows XP and Ubuntu

  - by Fabio Machado

  I am new to Ubuntu and at the moment I am trying to get Ubuntu 12.10 to one of my machines. The machine is a Pentium 4 @ 3.06, 2Gb RAM, 200GB Hard Drive and a NVidia GeForce 8800 GT. A few days ago, I tried Ubuntu without installing and it worked perfectly. Yesterday, I decided to formatted the hard drive and divide my hard drive into four partitions: 1 for the XP, 1 for Ubuntu, 1 for swamp and 1 where I will have my documents. Everything went great, I installed XP and then Ubuntu but I did something wrong on the partition window (Ubunto partion window) that I ended up without boot loader. This morning, I formatted everything again, installed XP and when I went to install Ubuntu (with the same DVD as before) the problems started. First, I had a black screen with a msg written with white text saying something like: unable to find a medium containing a live file system. After I burned another CD and tried again, I got stuck at the red dots (loading screen). I then went online and I read somewhere that it could be the CD, so I checked the integrity of the CD and everything was fine. I also unplugged all USBs connected to the computer and nothing changed. I goggled further options to try to solve my problem and some users suggested that people having these types of problems should try the alternate installation, which if I am not wrong is for networks. I then tried to install and yes the installation process was different from the normal CD, but it did get stuck on a page where it was doing something, like: ...finding ethd0 and it was stuck on the 100%. I tried USB installation as well and it also got stuck at the red dots (I do not have USB 3.0 on the computer in question). I have burned 5 different CD's and all at low speed. I checked the integrity and all are fine. I downloaded other distribution as well as other versions of Ubuntu and I still cannot install or even run the Live CD of Ubuntu or any other distribution. What is really annoying me is that everything was working perfectly before, when I first tried to install Ubuntu. Anyway, any help is welcome. Edit: My boot load is normal, no errors and all the hardware is working fine. I forgot to mention that after the loading screen (red dots) gets stuck, the DVD drive and the hard drive goes into idle state. I also restored the default values of the BIOS and no luck.

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• Equal Gifts Algorithm Problem

  - by 7Aces

  Problem Link - http://opc.iarcs.org.in/index.php/problems/EQGIFTS It is Lavanya's birthday and several families have been invited for the birthday party. As is customary, all of them have brought gifts for Lavanya as well as her brother Nikhil. Since their friends are all of the erudite kind, everyone has brought a pair of books. Unfortunately, the gift givers did not clearly indicate which book in the pair is for Lavanya and which one is for Nikhil. Now it is up to their father to divide up these books between them. He has decided that from each of these pairs, one book will go to Lavanya and one to Nikhil. Moreover, since Nikhil is quite a keen observer of the value of gifts, the books have to be divided in such a manner that the total value of the books for Lavanya is as close as possible to total value of the books for Nikhil. Since Lavanya and Nikhil are kids, no book that has been gifted will have a value higher than 300 Rupees... For the problem, I couldn't think of anything except recursion. The code I wrote is given below. But the problem is that the code is time-inefficient and gives TLE (Time Limit Exceeded) for 9 out of 10 test cases! What would be a better approach to the problem? Code - #include<cstdio> #include<climits> #include<algorithm> using namespace std; int n,g[150][2]; int diff(int a,int b,int f) { ++f; if(f==n) { if(a>b) { return a-b; } else { return b-a; } } return min(diff(a+g[f][0],b+g[f][1],f),diff(a+g[f][1],b+g[f][0],f)); } int main() { int i; scanf("%d",&n); for(i=0;i<n;++i) { scanf("%d%d",&g[i][0],&g[i][1]); } printf("%d",diff(g[0][0],g[0][1],0)); } Note - It is just a practice question, & is not part of a competition.

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• Au revoir, Python?

  - by GuySmiley

  I'm an ex-C++ programmer who's recently discovered (and fallen head-over-heels with) Python. I've taken some time to become reasonably fluent in Python, but I've encountered some troubling realities that may lead me to drop it as my language of choice, at least for the time being. I'm writing this in the hopes that someone out there can talk me out of it by convincing me that my concerns are easily circumvented within the bounds of the python universe. I picked up python while looking for a single flexible language that will allow me to build end-to-end working systems quickly on a variety of platforms. These include: - web services - mobile apps - cross-platform client apps for PC Development speed is more of a priority at the time-being than execution speed. However, in order to improve performance over time without requiring major re-writes or architectural changes I think it's imperative to be able to interface easily with Java. That way, I can use Java to optimize specific components as the application scales, without throwing away any code. As far as I can tell, my requirement for an enterprise-capable, platform-independent, fast language with a large developer base means it would have to be Java. .NET or C++ would not cut it due to their respective limitations. Also Java is clearly de rigeur for most mobile platforms. Unfortunately, tragically, there doesn't seem to be a good way to meet all these demands. Jython seems to be what I'm looking for in principle, except that it appears to be practically dead, with no one developing, supporting, or using it to any great degree. And also Jython seems too married to the Java libraries, as you can't use many of the CPython standard libraries with it, which has a major impact on the code you end up writing. The only other option that I can see is to use JPype wrapped in marshalling classes, which may work although it seems like a pain and I wonder if it would be worth it in the long run. On the other hand, everything I'm looking for seems to be readily available by using JRuby, which seems to be much better supported. As things stand, I think this is my best option. I'm sad about this because I absolutely love everything about Python, including the syntax. The perl-like constructs in Ruby just feel like such a step backwards to me in terms of readability, but at the end of the day most of the benefits of python are available in Ruby as well. So I ask you - am I missing something here? Much of what I've said is based on what I've read, so is this summary of the current landscape accurate, or is there some magical solution to the Python-Java divide that will snuff these concerns and allow me to comfortably stay in my happy Python place?

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• Space partitioning when everything is moving

  - by Roy T.

  Background Together with a friend I'm working on a 2D game that is set in space. To make it as immersive and interactive as possible we want there to be thousands of objects freely floating around, some clustered together, others adrift in empty space. Challenge To unburden the rendering and physics engine we need to implement some sort of spatial partitioning. There are two challenges we have to overcome. The first challenge is that everything is moving so reconstructing/updating the data structure has to be extremely cheap since it will have to be done every frame. The second challenge is the distribution of objects, as said before there might be clusters of objects together and vast bits of empty space and to make it even worse there is no boundary to space. Existing technologies I've looked at existing techniques like BSP-Trees, QuadTrees, kd-Trees and even R-Trees but as far as I can tell these data structures aren't a perfect fit since updating a lot of objects that have moved to other cells is relatively expensive. What I've tried I made the decision that I need a data structure that is more geared toward rapid insertion/update than on giving back the least amount of possible hits given a query. For that purpose I made the cells implicit so each object, given it's position, can calculate in which cell(s) it should be. Then I use a HashMap that maps cell-coordinates to an ArrayList (the contents of the cell). This works fairly well since there is no memory lost on 'empty' cells and its easy to calculate which cells to inspect. However creating all those ArrayLists (worst case N) is expensive and so is growing the HashMap a lot of times (although that is slightly mitigated by giving it a large initial capacity). Problem OK so this works but still isn't very fast. Now I can try to micro-optimize the JAVA code. However I'm not expecting too much of that since the profiler tells me that most time is spent in creating all those objects that I use to store the cells. I'm hoping that there are some other tricks/algorithms out there that make this a lot faster so here is what my ideal data structure looks like: The number one priority is fast updating/reconstructing of the entire data structure Its less important to finely divide the objects into equally sized bins, we can draw a few extra objects and do a few extra collision checks if that means that updating is a little bit faster Memory is not really important (PC game)

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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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• How To Build An Enterprise Application - Introduction

  - by Tuan Nguyen

  An enterprise application is a software which fulfills 4 core quality attributes: Reliability Flexibility Reusability Maintainability Reliability is the ability of a system or component to perform its required functions under stated conditions for a specific period of time. Because there are no ways more than testing to make sure a system is reliability, we can exchange the term reliability with the term testability. Flexibility is the ability of changing a system's core features without violating unrelated features or components. Although flexibility can helps us to achieve interoperability easily but the opposite is not true. For example, a program might run on multiple platforms, contains logic for many scenarios but that wouldn't mean it was flexibility if it forces us rewrite code in all components when we just want to change some aspects of a feature it had. Reusability is the ability of sharing one or more system's components for another system. We should just open a component's reusability in the context in which it is used. For example, we write classes that implement UI logic and deliver them to only classes which implementing UI. Maintainability is the ability of adding or removing features to a system after it was released. Maintainability consists of many factors such as readability, analyzability, extensibility therein extensibility is critical. Maintainability requires us to write code that is longer and complexer than normal but it doesn't mean we introduce unneccessarily complex code. We always try to make our code clear and transparent to everyone. An application enterprise is built on an enterprise design which consists of two parts: low-level design and high-level design. At low-level design, it focuses on building loose-coupled classes or components. Particularly, it recommends: Each class or component undertakes only single responsibility (design based on unit test) Classes or components implement and work through interfaces (design based on contract) Dependency relationship between classes and components could be injected at run-time (design based on dependency) At high-level design, it focuses on architecting system into tiers and layers. Particularly, it recommends: Divide system into subsystems for deployment. Each subsytem is called a tier. Typical, an enterprise application would have 3 tiers as illustrated in the following figure: Arrange classes and components to logical containers called layers. Typical, an enterprise application would have 5 layers as illustrated in the following figure

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• schedule compliance and keeping technical supports and resolving issues

  - by imays

  I am an entrepreneur of a small software developer company. The flagship product is developed by myself and my company grew up to 14 people. One of pride is that we've never have to be invested or loaned. The core development team is 5 people. 3 are seniors and 2 are juniors. After the first release, we've received many issues from our customers. Most of them are bug issues, customization needs, usage questions and upgrade requests. The issues from customers are incoming many times everyday, so it takes little time or much time of our developers. Because of our product is a software development kit(SDK) so most of questions can be answered only from our developers. And, for resolving bug issues, developers must be involved. Estimating time to resolve bug is hard. I fully understand it. However, our developers insist they cannot set the any due date of each project because they are busy doing technical supports and bug fixes by issues from customers everyday. Of course, they never do overwork. I suggested them an idea to divide the team into two parts: one for focusing on development by milestones, other for doing technical supports and bug fixes without setting due days. Then we could announce release plan officially. After the finish of release, two parts exchange the role for next milestone. However, they say they "NO, because it is impossible to share knowledge and design document fully." They still say they cannot set the release date and they request me to alter the due date flexibly. They does not fix the due date of each milestone. Fortunately, our company is not loaned and invested so we are not chocked. But I think it is bad idea to keep this situation. I know the story of ant and grasshopper. Our customers are tired of waiting forever of our release date. Companies consume limited time and money. If flexible due date without limit could be acceptable, could they accept flexible salary day? What is the root cause of our problem? All that I want is to fix and achieve precisely due date of each milestone without losing frequent technical supports. I think there must be solution for this situation. Please answer me. Thanks in advance. PS. Our tools and ways of project management are Trello, Mantis-like issue tracker, shared calendar software and scrum(collected cards into series of 'small and high completeness' projects).

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• Generating Report for NUnit

  - by thangchung

   All source codes for this post can be found at my github.Time ago, I received a request that people ask me how they can generate reports of the results of testing using NUnit? In fact, I may never do this. In the little world of my programming, I only care about the test results, red-green-refactoring, and that was it. When I got that question quite a bit unexpected, I knew that I could use NCover to generate reports, but reports of NCover too simple, it did not give us more details on the number of test cases, test methods, ... And I began to see about creating interesting report for NUnit.I was lucky to find an open source here. Its authors call it NUnit2Report, but one disadvantage is it only running on .NET 1.0. Indeed too old compared to the current version 4.0. And I try to download the preview, but I could not run. I had to open its source code and found that it uses XSLT to convert the output of NUnit results from XML to HTML. Nothing really special, because I also knew that after NUnit run output file extension is XML is created. Author only use this file to convert to HTML using XSLT. And I decided to convert it to. NET 4.0, because I will not have to code from scratch. Conversion work made me take some time, but was lucky that I finally have what I want. Thanks Gilles for the this OSS. I will send a mail to thank him for his efforts but put this out for the OSS. Now I will show people how to do it. I used the auto built NAnt and NUnit for running TestCase, and I use Selenium testing framework. After writing three TestCase using Selenium, I ran NUnit, and got the following results: There are 1 fail and 2s success. In the bin directory of this project will have the NUnit output file as shown below: Then I create a build file, and a bat file for easy running (can use PowerShell is here also.) Double click in the bat file to create a report like this:       Finally open the index.html file in the folder to view report. As everyone can see, it is the TestCase and divide very clearly, that I meet the requirements. This is really good. Once again I really thank NUnit2Report from Gilles. People can contact him via the mail address [email protected] or website  http://nunit2report.sourceforge.net. It really is useful to those who promised to QA. Hopefully this post will help anyone really interested in doing reports for NUnit.   

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• SQL – Biggest Concerns in a Data-Driven World

  - by Pinal Dave

  The ongoing chaos over Government Agency’s snooping has ignited a heated debate on privacy of personal data and its use by government and/or other institutions. It has created a feeling of disapproval and distrust among users. This incident proves to be a lesson for companies that are looking to leverage their business using a data driven approach. According to analysts, the goal of gathering personal information should be to deliver benefits to both the parties – the user as well as the data collector(government or business). Using data the right way is crucial, and companies need to deploy the right software applications and systems to ensure that their efforts are well-directed. However, there are various issues plaguing analysts regarding available software, which are highlighted below. According to a InformationWeek 2013 Survey of Analytics, Business Intelligence and Information Management where 541 business technology professionals contributed as respondents, it was discovered that the biggest concern was deemed to be the scarcity of expertise and high costs associated with the same. This concern was voiced by as many as 38% of the participants. A close second came out to be the issue of data warehouse appliance platforms being expensive, with 33% of those present believing it to be a huge roadblock. Another revelation made in this respect was that 31% professionals weren’t even sure how Data Analytics can create business opportunities for them. Another 17% shared that they found data platform technologies such as Hadoop and NoSQL technologies hard to learn. These results clearly pointed out that there are awareness and expertise issues that also need much attention. Unless the demand-supply gap of Business Intelligence professionals well versed in data analysis technologies is met, this divide is going to affect how companies make the most of their BI campaigns. One of the key action points that can be taken to salvage the situation, is to provide training on Data Analytics concepts. Koenig Solutions offer courses on many such technologies including a course on MCSE SQL Server 2012: BI Platform. So it’s time to brush up your skills and get down to work in a data driven world that awaits you ahead. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• Wrong statistics in AUX_STATS$ might puzzle the optimizer

  - by Mike Dietrich

  We do recommend the creation of System Statistics for quite a long time. Since Oracle 9i the optimizer works with a CPU and IO cost based model. And in order to give the optimizer some knowledge about the IO subsystem's performance and throughput - once System Statistics are collected - they'll get stored in AUX_STATS$. For this purpose in the old Oracle 9i days some default values had been defined - and you'll still find those defaults in Oracle Database 11g Release 2 in AUX_STATS$. But these old values don't reflect the performance of modern IO systems. So it might be a good best practice post upgrade to create fresh System Statistics if you haven't done this before.  You can collect System Statistics with: exec DBMS_STATS.GATHER_SYSTEM_STATS('start'); and end it later by executing: exec DBMS_STATS.GATHER_SYSTEM_STATS('stop'); You could also run DBMS_STATS.GATHER_SYSTEM_STATS('interval', interval=>N) instead where N is the number of minutes when statistics gathering is stopped automatically. Please make sure you'll do this on a real workload period. It won't make sense to gather these values while the database is in an idle state. You should do this ideally for several hours. It doesn't affect performance in a negative way as the values are anyway collected in V$SYSSTAT and V$SESSTAT. And in case you'd like to delete the stats and revert to the old default values you'd simply execute:exec DBMS_STATS.DELETE_SYSTEM_STATS; The tricky thing in Oracle Database 11.2 - and that's why I'm actually writing this blog post today - is bug9842771. This leads to wrong values in AUX_STATS$ for SREADTIM and MREADTIM by factor 1000 guiding the optimizer sometimes into the totally wrong directon. The workaround is to overwrite these values manually and divide them by 1000. Use the DBMS_STATS.SET_SYSTEM_STATS procedure. See this MOS Note:9842771.8 for the above bug for some further information. This issue is fixed in Oracle Database 11.2.0.3 and above. To get some background information about the statistics collected in please read this section in the Oracle Database 11.2 Performance Tuning Guide. And gathering System Statistics might have some implication if you have mixed workloads - and interacts with DB_FILE_MULTIBLOCK_READ_COUNT. For more information please read section 13.4.1.2.

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• How to implement an intelligent enemy in a shoot-em-up?

  - by bummzack

  Imagine a very simple shoot-em-up, something we all know: You're the player (green). Your movement is restricted to the X axis. Our enemy (or enemies) is at the top of the screen, his movement is also restricted to the X axis. The player fires bullets (yellow) at the enemy. I'd like to implement an A.I. for the enemy that should be really good at avoiding the players bullets. My first idea was to divide the screen into discrete sections and assign weights to them: There are two weights: The "bullet-weight" (grey) is the danger imposed by a bullet. The closer the bullet is to the enemy, the higher the "bullet-weight" (0..1, where 1 is highest danger). Lanes without a bullet have a weight of 0. The second weight is the "distance-weight" (lime-green). For every lane I add 0.2 movement cost (this value is kinda arbitrary now and could be tweaked). Then I simply add the weights (white) and go to the lane with the lowest weight (red). But this approach has an obvious flaw, because it can easily miss local minima as the optimal place to go would be simply between two incoming bullets (as denoted with the white arrow). So here's what I'm looking for: Should find a way through bullet-storm, even when there's no place that doesn't impose a threat of a bullet. Enemy can reliably dodge bullets by picking an optimal (or almost optimal) solution. Algorithm should be able to factor in bullet movement speed (as they might move with different velocities). Ways to tweak the algorithm so that different levels of difficulty can be applied (dumb to super-intelligent enemies). Algorithm should allow different goals, as the enemy doesn't only want to evade bullets, he should also be able to shoot the player. That means that positions where the enemy can fire at the player should be preferred when dodging bullets. So how would you tackle this? Contrary to other games of this genre, I'd like to have only a few, but very "skilled" enemies instead of masses of dumb enemies.

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• What is this algorithm for converting strings into numbers called?

  - by CodexArcanum

  I've been doing some work in Parsec recently, and for my toy language I wanted multi-based fractional numbers to be expressible. After digging around in Parsec's source a bit, I found their implementation of a floating-point number parser, and copied it to make the needed modifications. So I understand what this code does, and vaguely why (I haven't worked out the math fully yet, but I think I get the gist). But where did it come from? This seems like a pretty clever way to turn strings into floats and ints, is there a name for this algorithm? Or is it just something basic that's a hole in my knowledge? Did the folks behind Parsec devise it? Here's the code, first for integers: number' :: Integer -> Parser Integer number' base = do { digits <- many1 ( oneOf ( sigilRange base )) ; let n = foldl (\x d -> base * x + toInteger (convertDigit base d)) 0 digits ; seq n (return n) } So the basic idea here is that digits contains the string representing the whole number part, ie "192". The foldl converts each digit individually into a number, then adds that to the running total multiplied by the base, which means that by the end each digit has been multiplied by the correct factor (in aggregate) to position it. The fractional part is even more interesting: fraction' :: Integer -> Parser Double fraction' base = do { digits <- many1 ( oneOf ( sigilRange base )) ; let base' = fromIntegral base ; let f = foldr (\d x -> (x + fromIntegral (convertDigit base d))/base') 0.0 digits ; seq f (return f) Same general idea, but now a foldr and using repeated division. I don't quite understand why you add first and then divide for the fraction, but multiply first then add for the whole. I know it works, just haven't sorted out why. Anyway, I feel dumb not working it out myself, it's very simple and clever looking at it. Is there a name for this algorithm? Maybe the imperative version using a loop would be more familiar?

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• Why does my code dividing a 2D array into chunks fail?

  - by Borog

  I have a 2D-Array representing my world. I want to divide this huge thing into smaller chunks to make collision detection easier. I have a Chunk class that consists only of another 2D Array with a specific width and height and I want to iterate through the world, create new Chunks and add them to a list (or maybe a Map with Coordinates as the key; we'll see about that). world = new World(8192, 1024); Integer[][] chunkArray; for(int a = 0; a < map.getHeight() / Chunk.chunkHeight; a++) { for(int b = 0; b < map.getWidth() / Chunk.chunkWidth; b++) { Chunk chunk = new Chunk(); chunkArray = new Integer[Chunk.chunkWidth][Chunk.chunkHeight]; for(int x = Chunk.chunkHeight*a; x < Chunk.chunkHeight*(a+1); x++) { for(int y = Chunk.chunkWidth*b; y < Chunk.chunkWidth*(b+1); y++) { // Yes, the tileMap actually is [height][width] I'll have // to fix that somewhere down the line -.- chunkArray[y][x] = map.getTileMap()[x*a][y*b]; // TODO:Attach to chunk } } chunkList.add(chunk); } } System.out.println(chunkList.size()); The two outer loops get a new chunk in a specific row and column. I do that by dividing the overall size of the map by the chunkSize. The inner loops then fill a new chunkArray and attach it to the chunk. But somehow my maths is broken here. Let's assume the chunkHeight = chunkWidth = 64. For the first Array I want to start at [0][0] and go until [63][63]. For the next I want to start at [64][64] and go until [127][127] and so on. But I get an out of bounds exception and can't figure out why. Any help appreciated! Actually I think I know where the problem lies: chunkArray[y][x] can't work, because y goes from 0-63 just in the first iteration. Afterwards it goes from 64-127, so sure it is out of bounds. Still no nice solution though :/ EDIT: if(y < Chunk.chunkWidth && x < Chunk.chunkHeight) chunkArray[y][x] = map.getTileMap()[y][x]; This works for the first iteration... now I need to get the commonly accepted formula.

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• OTN Virtual Technology Summit - July 9 - Middleware Track

  - by OTN ArchBeat

  The Architecture of Analytics: Big Time Big Data and Business Intelligence This four-session track, part of the free OTN Virtual Technology Summit on July 9, will present a solution architect's perspective on how business intelligence products in Oracle's Fusion Middleware family and beyond fit into an effective big data architecture, offering insight and expertise from Oracle ACE Directors and product team experts specializing in business Intelligence to help you meet your big data business intelligence challenges. Register now! Sessions Oracle Big Data Appliance Case Study: Using Big Data to Analyze Cancer-Genome Relationships Tom Plunkett, Lead Author of the Oracle Big Data Handbook What does it take to build an award winning Big Data solution? This presentation takes a deep technical dive into the use of the Oracle Big Data Appliance in a project for the National Cancer Institute's Frederick National Laboratory for Cancer Research. The Frederick National Laboratory and the Oracle team won several awards for analyzing relationships between genomes and cancer subtypes with big data, including the 2012 Government Big Data Solutions Award, the 2013 Excellence.Gov Finalist for Innovation, and the 2013 ComputerWorld Honors Laureate for Innovation. [30 mins] Getting Value from Big Data Variety Richard Tomlinson, Director, Product Management, Oracle Big data variety implies big data complexity. Performing analytics on diverse data typically involves mashing up structured, semi-structured and unstructured content. So how can we do this effectively to get real value? How do we relate diverse content so we can start to analyze it? This session looks at how we approach this tricky problem using Endeca Information Discovery. [30 mins] How To Leverage Your Investment In Oracle Business Intelligence Enterprise Edition Within a Big Data Architecture Oracle ACE Director Kevin McGinley More and more organizations are realizing the value Big Data technologies contribute to the return on investment in Analytics. But as an increasing variety of data types reside in different data stores, organizations are finding that a unified Analytics layer can help bridge the divide in modern data architectures. This session will examine how you can enable Oracle Business Intelligence Enterprise Edition (OBIEE) to play a role in a unified Analytics layer and the benefits and use cases for doing so. [30 mins] Oracle Data Integrator 12c As Your Big Data Data Integration Hub Oracle ACE Director Mark Rittman Oracle Data Integrator 12c (ODI12c), as well as being able to integrate and transform data from application and database data sources, also has the ability to load, transform and orchestrate data loads to and from Big Data sources. In this session, we'll look at ODI12c's ability to load data from Hadoop, Hive, NoSQL and file sources, transform that data using Hive and MapReduce processing across the Hadoop cluster, and then bulk-load that data into an Oracle Data Warehouse using Oracle Big Data Connectors. We will also look at how ODI12c enables ETL-offloading to a Hadoop cluster, with some tips and techniques on real-time capture into a Hadoop data reservoir and techniques and limitations when performing ETL on big data sources. [90 mins] Register now!

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• A solution for a PHP website without a framework

  - by lortabac

  One of our customers asked us to add some dynamic functionality to an existent website, made of several static HTML pages. We normally work with an MVC framework (mostly CodeIgniter), but in this case moving everything to a framework would require too much time. Since it is not a big project, not having the full functionality of a framework is not a problem. But the question is how to keep code clean. The solution I came up with is to divide code in libraries (the application's API) and models. So inside HTML there will only be API calls, and readability will not be sacrificed. I implemented this with a sort of static Registry (sorry if I'm wrong, I am not a design pattern expert): <?php class Custom_framework { //Global database instance private static $db; //Registered models private static $models = array(); //Registered libraries private static $libraries = array(); //Returns a database class instance static public function get_db(){ if(isset(self::$db)){ //If instance exists, returns it return self::$db; } else { //If instance doesn't exists, creates it self::$db = new DB; return self::$db; } } //Returns a model instance static public function get_model($model_name){ if(isset(self::$models[$model_name])){ //If instance exists, returns it return self::$models[$model_name]; } else { //If instance doesn't exists, creates it if(is_file(ROOT_DIR . 'application/models/' . $model_name . '.php')){ include_once ROOT_DIR . 'application/models/' . $model_name . '.php'; self::$models[$model_name] = new $model_name; return self::$models[$model_name]; } else { return FALSE; } } } //Returns a library instance static public function get_library($library_name){ if(isset(self::$libraries[$library_name])){ //If instance exists, returns it return self::$libraries[$library_name]; } else { //If instance doesn't exists, creates it if(is_file(ROOT_DIR . 'application/libraries/' . $library_name . '.php')){ include_once ROOT_DIR . 'application/libraries/' . $library_name . '.php'; self::$libraries[$library_name] = new $library_name; return self::$libraries[$library_name]; } else { return FALSE; } } } } Inside HTML, API methods are accessed like this: <?php echo Custom_framework::get_library('My_library')->my_method(); ?> It looks to me as a practical solution. But I wonder what its drawbacks are, and what the possible alternatives.

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• rotating spheres

  - by Dave

  I want to continuously rotate 2 spheres, however the rotation does not seem to work. Here is my code: float angle = 0.0f; void light(){ glEnable(GL_LIGHTING); glEnable(GL_LIGHT0); glEnable(GL_LIGHT1); // Create light components GLfloat positionlight1[] = { 9.0, 5.0, 1.0, 0.0 }; GLfloat positionlight2[] = {0.2,2.5,1.3,0.0}; GLfloat light_ambient1[] = { 0.0, 0.0, 1.0, 1.0}; GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 }; glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient1); glLightfv(GL_LIGHT1, GL_DIFFUSE, light_diffuse); glLightfv(GL_LIGHT0, GL_POSITION, positionlight1); glLightfv(GL_LIGHT1, GL_POSITION, positionlight2); } void changeSize(int w, int h) { if (h==0) // Prevent A Divide By Zero By { h=1; // Making Height Equal One } glMatrixMode(GL_PROJECTION); // Select The Projection Matrix glLoadIdentity(); // Reset The Projection Matrix glViewport(0,0,w,h);// Reset The Current Viewport // Calculate The Aspect Ratio Of The Window gluPerspective(45.0f,(GLfloat)w/(GLfloat)h,0.1f,100.0f); glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix // Reset The Modelview Matrix } void renderScene(void) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glPushMatrix(); //set where to start the current object glTranslatef(0.0,1.2,-6); glRotatef(angle,0,1.2,-6); glutSolidSphere(1,50,50); glPopMatrix(); //end the current object transformations glPushMatrix(); //set where to start the current object glTranslatef(0.0,-2,-6); glRotatef(angle,0,-2,-6); glutSolidSphere(0.5,50,50); glPopMatrix(); //end the current object transformations angle=+0.1; glutSwapBuffers(); } int main(int argc, char **argv) { // init GLUT and create window glutInit(&argc, argv); glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA); glutInitWindowPosition(100,100); glutInitWindowSize(500,500); glutCreateWindow("Hello World"); // register callbacks light(); glutDisplayFunc(renderScene); glutReshapeFunc(changeSize); glutIdleFunc(renderScene); // enter GLUT event processing loop glutMainLoop(); return 1; } Graphicstest::Graphicstest(void) { } In the renderscene where i draw,translate and rotate my 2 spheres. It does not seem to rotate the spheres continuously. What am i doing wrong?

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