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  • SQL SERVER – Developer Training Resources and Summary Roundup

    - by pinaldave
    It is always pleasure for any author when other renowned authors in the industry write about you. Earlier I wrote a five part blog series on Developer Training and I have received a phenomenal response to the series. I have received plenty of comments, questions and feedback. I thought it would be nice to sum up the whole series as well answer a few of the questions received. Quick Recap Developer Training - Importance and Significance - Part 1 In this part we discussed the importance of training in the real world. The most important and valuable resource any company is its employee. Employees who have been well-trained will be better at their jobs and produce a better product.  An employee who is well trained obviously knows more about their job and all the technical aspects. I have a very high opinion about training employees and it is the most important task. Developer Training – Employee Morals and Ethics – Part 2 In this part we discussed the most crucial components of training. Often employees are expecting the company to pay for their training and the company expresses no interest in training the employee. Quite often training expenses are the real issue for both the employee and employer. There are companies that pay for 100% of the expenses and there are employees who opt for training on their own expense during their personal time. Training is often looked at as vacation by employee and employers and we need to change this mind-set. One of the ways is to report back the learning to your manager and implement newly learned knowledge in day-to-day work. Developer Training – Difficult Questions and Alternative Perspective - Part 3 This part was the most difficult to write as I tried to address a few difficult questions and answers. Training is such a sensitive issue that many developers when not receiving chance for training think about leaving the organization. The manager often feels pressure to accommodate every single employee for training even though his training budget is limited. It is indeed the responsibility of the developer to get maximum advantage from the training. Training immediately helps organizations but stays as a part of an employee’s knowledge forever. Developer Training – Various Options for Developer Training – Part 4 In this part I tried to explore a few methods and options for training. The generic feedback I received on this blog post was short and I should have explored each of the subject of the training in details. I believe there are two big buckets of training 1) Instructor Lead Training and 2) Self Lead Training. The common element between both the methods is “learning material”. Learning material can be of any format – videos, books, paper notes or just a plain black board. Instructor-led training is a very effective mode but not possible every single time. During the course of the developer’s career, one has to learn lots of new technology and it is almost impossible to have a quality trainer available on that subject at that time. Books are most effective and proven methods, however, it always helps if someone explains the concepts of the book with a demonstration. In recent times I have started to believe in online trainings which leads to a hybrid experience. Online trainings take the best part of the books and the best part of the instructor-led training and gives effective training in a matter of hours. Developer Training – A Conclusive Summary- Part 5 In this part, I shared what I was continuously thinking about developer training. There is no better teacher than oneself. There is no better motivation than a personal desire to learn new technology. Honestly there is nothing more personal learning. That “change is the only constant” and “adapt & overcome” are the essential lessons of life. One cannot stop the learning and resist the change. In the IT industry “ego of knowing all” and the “resistance to change” are the most challenging issues. Once someone overcomes them, life is much easier. I believe that proper and appropriate high quality training can help to address the burning issues. Opinion of Friends I invited a few of my friends to express their opinion about developer training and here are their opinions. I am listing them here in the order of the blog post publishing date. Nakul Vachhrajani - Developer Trainings-Importance, Benefits, Tips and follow-up Nakul’s sums of many of the concepts which are complementary to my blog posts. Nakul addresses the burning question of developer training with different angles. I am personally very impressed by his following statement - “Being skilled does not mean having just a stack of certifications, but it also means having an understanding about the internals of the products that you are working on – and using that knowledge to improve the efficiency & productivity at the workplace in turn resulting in better products, better consulting abilities and a happier self.” Nakul also suggests the online training options of Pluralsight. Vinod Kumar - Training–a necessity or bonus Vinod Kumar comes up with excellent follow up on developer training. Vinod is known for his inspirational writing about SQL Server. Vinod starts with a story of a student who is extremely eager to learn the wisdom of life from a monk but the monk does not accept him as a disciple for a long time. The conversation between student and monk is indeed an essence of all learning. We all want to learn quickly and be successful but the most important thing in life is to have the right attitude towards learning and more so towards life. The blog post end with a very important thought about how to avoid the famous excuse – “I don’t have enough time.” Ritesh Shah - Training – useful or useless? Ritesh brings up very important concept related to training. Ritesh in his meticulous style explains why training is an important and lifelong process. Training must not stop at any age but should continue forever. The moment training stops, progress stops along with. Paras Doshi - Professional Development Resource Paras is known for his to–the-point writing, and has summarized the five part series very precisely. He read the five part series and created a digest summary of the blog post. If you are in a rush and have no time to read my five series – I suggest you read his blog post. Training Resources I am often asked what the best resources for learning new technology are. This is the most difficult question EVER. There are plenty of good training resources available. When it is about training our needs are different, our preference of learning is different and we all have an opinion. Additionally, we all are located in different geographic locations worldwide and there is no way one solution will fit all. However, let me list a few of the training resources which I have built so far and you can consume them if you find it relevant to your need. SQL Server Books SQL Server Interview Questions and Answers SQL Wait Stats SQL Programming Joes 2 Pros SQL Server Video Tutorials SQL Server Questions and Answers SQL Server Performance: Indexing Basics SQL Server Performance: Introduction to Query Tuning SQL in Sixty Seconds Series of Sixty Seconds Learning Video on YouTube Trust me worldwide web is very big and there are plenty of high quality learning materials available worldwide – trainer-led as well online. I suggest you explore various options and make the best choice for yourself. Remember, training is your personal journey and it should never stop. Are you ready? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Developer Training, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQLAuthority News – Memories at Anniversary of SQL Wait Stats Book

    - by pinaldave
    SQL Wait Stats About a year ago, I had very proud moment. I had published my second book SQL Server Wait Stats with me as a primary author. It has been a long journey since then. The book got great response and it was widely accepted in the community. It was first of its kind of book written specifically on Wait Stats and Performance. The book was based on my earlier month long series written on the same subject SQL Server Wait Stats. Today, on the anniversary of the book, lots of things come to my mind let me share a few here. Idea behind Blog Series A very common question I often receive is why I wrote a 30 day series on Wait Stats. There were two reasons for it. 1) I have been working with SQL Server for a long time and have troubleshoot more than hundreds of SQL Server which are related to performance tuning. It was a great experience and it taught me a lot of new things. I always documented my experience. After a while I found that I was able to completely rely on my own notes when I was troubleshooting any servers. It is right then I decided to document my experience for the community. 2) While working with wait stats there were a few things, which I thought I knew it well as they were working. However, there was always a fear in the back of mind that what happens if what I believed was incorrect and I was on the wrong path all the time. There was only one way to get it validated. Put it out in front community with my understanding and request further help to improve my understanding. It worked, it worked beautifully. I received plenty of conversations, emails and comments. I refined my content based on various conversations and make it more relevant and near accurate. I guess above two are the major reasons for beginning my journey on writing Wait Stats blog series. Idea behind Book After writing a blog series there was a good amount of request I keep on receiving that I should convert it to eBook or proper book as reading blog posts is great but it goes not give a comprehensive understanding of the subject. The very common feedback from users who were beginning the subject that they will prefer to read it in a structured method. After hearing the feedback for more than 4 months, I decided to write a book based on the blog posts. When I envisioned book, I wanted to make sure this book addresses the wait stats concepts from the fundamentals and fill the gaps of blogs I wrote earlier. Rick Morelan and Joes 2 Pros Team I must acknowledge my co-author Rick Morelan for his unconditional support in writing this book. I had already authored one book before I published this book. The experience to write the book was out of the world. Writing blog posts are much much easier than writing books. The efforts it takes to write a book is 100 times more even though the content is ready. I could have not done it myself if there was not tremendous support of my co-author and editor’s team. We spend days and days researching and discussing various concepts covered in the book. When we were in doubt we reached out to experts as well did a practical reproduction of the scenarios to validate the concepts and claims. After continuous 3 months of hard work we were able to get this book out in the community. September 1st – the lucky day Well, we had to select any day to publish the books. When book was completed in August last week we felt very glad. We all had worked hard and having a sample draft book in hand was feeling like having a newborn baby in our hand. Every time my books are published I feel the same joy which I had when my daughter was born. The feeling of holding a new book in hand is the (almost) same feeling as holding newborn baby. I am excited. For me September 1st has been the luckiest day in mind life. My daughter Shaivi was born on September 1st. Since then every September first has been excellent day and have taken me to the next step in life. I believe anything and everything I do on September 1st it is turning out to be successful and blessed. Rick and I had finished a book in the last week of August. We sent it to the publisher (printer) and asked him to take the book live as soon as possible. We did not decide on any date as we wanted the book to get out as fast as it can. Interesting enough, the publisher/printer selected September 1st for publishing the book. He published the book on 1st September and I knew it at the same time that this book will go next level. Book Model – The Most Beautiful Girl We were done with book. We had no budget left for marketing. Rick and I had a long conversation regarding how to spread the words for the book so it can reach to many people. While we were talking about marketing Rick come up with the idea that we should hire a most beautiful girl around who acknowledge our book and genuinely care for book. It was a difficult task and Rick asked me to find a more beautiful girl. I am a father and the most beautiful girl for me my daughter. This was not a difficult task for me. Rick had given me task to find the most beautiful girl and I just could not think of anyone else than my own daughter. I still do not know what Rick thought about this idea but I had already made up my mind. You can see the detailed blog post here. The Fun Experiments Book Signing Event We had lots of fun moments along this book. We have given away more books to people for free than we have sold them actually. We had done book signing events, contests, and just plain give away when we found people can be benefited from this book. There was never an intention to make money and get rich. We just wanted that more and more people know about this new concept and learn from it. Today when I look back to the earnings there is nothing much we have earned if you talk about dollars. However the best reward which we have received is the satisfaction and love of community. The amount of emails, conversations we have so far received for this book is over thousands. We had fun writing this book, it was indeed a very satisfying journey. I have earned lots of friends while learning and exploring. Availability The book is one year old but still very relevant when it is about performance tuning. It is available at various online book stores. If you have read the book, do let me know what you think of it. Amazon | Kindle | Flipkart | Indiaplaza Reference:  Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority, SQLAuthority Book Review, T SQL, Technology

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  • Company Review: Google Products

    Google, Inc offers an array of products and services to all of its end-users. However their search capabilities are the foundation for Google’s current success and their primary business focus. Currently, Google offers over twenty different search applications that allow users to search the internet for books, maps, videos, images, products and much more. Their product decisions have allowed users demands to be met while focusing on the free based model. This allows users to access Google data free of charge and indirectly gives Google a strong competitive advantage of other competitors along with the accuracy of the search results. According to Google, Inc, they offer the following types of searching capabilities: Alerts Get email updates on the topics of your choice Blog Search Find blogs on your favorite topics  Books Search the full text of books  Custom Search Create a customized search experience for your community  Desktop Search and personalize your computer  Dictionary Search for definitions of words and phrases Directory Search the web, organized by topic or category Earth Explore the world from your computer Finance Business info, news and interactive charts GOOG-411 Find and connect for free with businesses from your phone  Images Search for images on the web Maps View maps and directions News Search thousands of news stories Patent Search Search the full text of US Patents Product Search Search for stuff to buy Scholar Search scholarly papers Toolbar Add a search box to your browser Trends Explore past and present search trends Videos Search for videos on the web Web Search Search billions of web pages Web Search Features Find movies, music, stocks, books and more mapping Google’s free based business model is only one way it differentiates itself from its competition. There is also a strong focus on the accuracy of search results and the speed in which they are returned to the end-user. Quality function deployment (QFD) is a structured method used to help connect user needs to the design features of a project proposed to address those needs. This method is particularly useful in accounting for needs that are not easily articulated or precisely defined according to the U. S. Department of Transportation Federal Highway Administration. Due to the fact that QFD is so customer driven Google is always in a constant state of change in attempt to reengineer its search algorithms, and other dependant systems so that end-users requirements are constantly being met. Value engineering is a key example of this, Google is constantly trying to improve all aspects of its products, improve system maintainability, and system interoperability. Bridgefield Group defines value engineering as an organized methodology that identifies and selects the lowest lifecycle cost options in design, materials and processes that achieves the desired level of performance, reliability and customer satisfaction. In addition, it seeks to remove unnecessary costs in the above areas and is often a joint effort with cross-functional internal teams and relevant suppliers. Common issues that appear when developing large scale systems like Google’s search applications include modular design of a product and/or service and providing accurate value analysis. A design approach that adheres to four fundamental tenets of cohesiveness, encapsulation, self-containment, and high binding to design a system component as an independently operable unit subject to change is how the Open System Joint Task Force defines modular design. More specifically M. S. Schmaltz defines modular software design as having a large collection of statements strung together in one partition of in-line code; we segment or divide the statements into logical groups called modules. Each module performs one or two tasks, and then passes control to another module. By breaking up the code into "bite-sized chunks", so to speak, we are able to better control the flow of data and control. This is especially true in large software systems. Value analysis is a process to evaluate products and services based on effectiveness, safety, and cost. Value analysis involves assessing the quality as well as the cost of a product or service as defined by the Healthcare Financial Management Association.  “Operations Management deals with the design and management of products, processes, services and supply chains. It considers the acquisition, development, and utilization of resources that firms need to deliver the goods and services their clients want.” (MIT,2010) Google, Inc encourages an open environment between all employees, also known as Googlers. This is reinforced by a cross-section team or cross-functional teams comprised from multiple departments assigned to every project so that every department like marketing, finance, and quality assurance has input on every project. In addition, Google is known for their openness to new ideas regardless of the status or seniority of an employee. In fact, Google allows for 20% of an employee’s time can be devoted to developing new ideas and/or pet projects. HumTech.com defines a cross-functional team as a collection of people with varied levels of skills and experience brought together to accomplish a task. As the name implies, Cross-Functional Team members come from different organizational units. Cross-Functional Teams may be permanent or ad hoc. Google’s search application product strategy primarily focuses on mass customization. This is allows Google to create a base search application and allows results to be returned to the end-users quickly based on specific parameters and search settings. In addition, they also store the data that is returned in case other desire the same results based on other end-users supplying the same customized settings. This allows Google to appear to render search results in virtually real-time to the user while allowing for complete customization of the searching criteria. Greg Vogl, a professor at Uganda Martyrs University, defines mass customization as when a business gives its customers the opportunity to tailor its products or services to the customer's specifications. The IT staff at Google play a key role in ensuring that the search application’s product strategy is maintained simply because the IT staff designs, develops, and maintains all of their proprietary applications. In fact, they also maintain all network infrastructure to ensure that it is available to all end-users. References: http://www.google.com/intl/en/options/ http://ops.fhwa.dot.gov/freight/publications/ftat_user_guide/sec5.htm http://www.bridgefieldgroup.com/bridgefieldgroup/glos9.htm#V http://www.acq.osd.mil/osjtf/termsdef.html http://www.cise.ufl.edu/~mssz/Pascal-CGS2462/prog-dsn.html http://www.hfma.org/publications/business_caring_newsletter/exclusives/Supply+and+Inventory+Terms+Defined.htm http://mitsloan.mit.edu/omg/om-definition.php http://www.humtech.com/opm/grtl/ols/ols3.cfm http://www.gregvogl.net/courses/mis1/glossary.htm

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  • unable to update gridview

    - by bhakti
    Please help ,i have added update/edit command button in gridview so to update data in my sql server database but am unable to do it. Data is not updated in database . ======code for onrowupdate======================================== protected void gRowUpdate(object sender, GridViewUpdateEventArgs e) { Books b = null; b = new Books(); DataTable dt=null; GridView g = (GridView)sender; try { dt=new DataTable(); b = new Books(); b.author = Convert.ToString(g.Rows[e.RowIndex].FindControl("Author")); b.bookID = Convert.ToInt32(g.Rows[e.RowIndex].FindControl("BookID")); b.title = Convert.ToString(g.Rows[e.RowIndex].FindControl("Title")); b.price = Convert.ToDouble(g.Rows[e.RowIndex].FindControl("Price")); // b.rec = Convert.ToString(g.Rows[e.RowIndex].FindControl("Date_of_reciept")); b.ed = Convert.ToString(g.Rows[e.RowIndex].FindControl("Edition")); b.bill = Convert.ToString(g.Rows[e.RowIndex].FindControl("Edition")); b.cre_by = Convert.ToString(g.Rows[e.RowIndex].FindControl("Edition")); b.src = Convert.ToString(g.Rows[e.RowIndex].FindControl("Edition")); b.pages = Convert.ToInt32(g.Rows[e.RowIndex].FindControl("Edition")); b.pub = Convert.ToString(g.Rows[e.RowIndex].FindControl("Edition")); b.mod_by = Convert.ToString(g.Rows[e.RowIndex].FindControl("Edition")); b.remark = Convert.ToString(g.Rows[e.RowIndex].FindControl("Edition")); // b.year = Convert.ToString(g.Rows[e.RowIndex].FindControl("Edition")); b.updatebook(b); g.EditIndex = -1; dt = b.GetAllBooks(); g.DataSource = dt; g.DataBind(); } catch (Exception ex) { throw (ex); } finally { b = null; } } ===================My stored procedure for update book able to update database by exec in sqlserver mgmt studio========================== set ANSI_NULLS ON set QUOTED_IDENTIFIER ON go ALTER PROCEDURE [dbo].[usp_updatebook] @bookid bigint, @author varchar(50), @title varchar(50), @price bigint, @src_equisition varchar(50), @bill_no varchar(50), @publisher varchar(50), @pages bigint, @remark varchar(50), @edition varchar(50), @created_by varchar(50), @modified_by varchar(50) /*@date_of_reciept datetime, @year_of_publication datetime*/ AS declare @modified_on datetime set @modified_on=getdate() UPDATE books SET author=@author, title=@title, price=@price, src_equisition=@src_equisition, bill_no=@bill_no, publisher=@publisher, /*Date_of_reciept=@date_of_reciept,*/ pages=@pages, remark=@remark, edition=@edition, /*Year_of_publication=@year_of_publication,*/ created_by=@created_by, modified_on=@modified_on, modified_by=@modified_by WHERE bookid=@bookid ========================class library function for update==================== public void updatebook(Books b) { DataAccess dbAccess = null; SqlCommand cmd = null; try { dbAccess = new DataAccess(); cmd = dbAccess.GetSQLCommand("usp_updatebook", CommandType.StoredProcedure); cmd.Parameters.Add("@bookid", SqlDbType.VarChar, 50).Value = b.bookID; cmd.Parameters.Add("@author", SqlDbType.VarChar, 50).Value = b.author; cmd.Parameters.Add("@title", SqlDbType.VarChar, 50).Value = b.title; cmd.Parameters.Add("@price", SqlDbType.Money).Value = b.price; cmd.Parameters.Add("@publisher", SqlDbType.VarChar, 50).Value = b.pub; // cmd.Parameters.Add("@year_of_publication", SqlDbType.DateTime).Value =Convert.ToDateTime( b.year); cmd.Parameters.Add("@src_equisition", SqlDbType.VarChar, 50).Value = b.src; cmd.Parameters.Add("@bill_no", SqlDbType.VarChar, 50).Value = b.bill; cmd.Parameters.Add("@remark", SqlDbType.VarChar, 50).Value = b.remark; cmd.Parameters.Add("@pages", SqlDbType.Int).Value = b.pages; cmd.Parameters.Add("@edition", SqlDbType.VarChar, 50).Value = b.ed; // cmd.Parameters.Add("@date_of_reciept", SqlDbType.DateTime).Value = Convert.ToDateTime(b.rec); // cmd.Parameters.Add("@created_on", SqlDbType.DateTime).Value = Convert.ToDateTime(b.cre_on); cmd.Parameters.Add("@created_by", SqlDbType.VarChar, 50).Value = b.cre_by; //cmd.Parameters.Add("@modified_on", SqlDbType.DateTime).Value = Convert.ToDateTime(b.mod_on); cmd.Parameters.Add("@modified_by", SqlDbType.VarChar, 50).Value = b.mod_by; cmd.ExecuteNonQuery(); } catch (Exception ex) { throw (ex); } finally { if (cmd.Connection != null && cmd.Connection.State == ConnectionState.Open) cmd.Connection.Close(); dbAccess = null; cmd = null; } } I have also tried to do update by following way protected void gv1_updating(object sender, GridViewUpdateEventArgs e) { GridView g = (GridView)sender; abc a = new abc(); DataTable dt = new DataTable(); try { a.cd_Id = Convert.ToInt32(g.DataKeys[e.RowIndex].Values[0].ToString()); //TextBox b = (TextBox)g.Rows[e.RowIndex].Cells[0].FindControl("cd_id"); TextBox c = (TextBox)g.Rows[e.RowIndex].Cells[2].FindControl("cd_name"); TextBox d = (TextBox)g.Rows[e.RowIndex].Cells[3].FindControl("version"); TextBox f = (TextBox)g.Rows[e.RowIndex].Cells[4].FindControl("company"); TextBox h = (TextBox)g.Rows[e.RowIndex].Cells[6].FindControl("created_by"); TextBox i = (TextBox)g.Rows[e.RowIndex].Cells[8].FindControl("modified_by"); //a.cd_Id = Convert.ToInt32(b.Text); a.cd_name = c.Text; a.ver = d.Text; a.comp = f.Text; a.cre_by = h.Text; a.mod_by = i.Text; a.updateDigi(a); g.EditIndex = -1; dt = a.GetAllDigi(); g.DataSource = dt; g.DataBind(); } catch(Exception ex) { throw (ex); } finally { dt = null; a = null; g = null; } } =================== but have error of Index out of range exception========= please do reply,thanxs in advance

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  • May 20th Links: ASP.NET MVC, ASP.NET, .NET 4, VS 2010, Silverlight

    - by ScottGu
    Here is the latest in my link-listing series.  Also check out my VS 2010 and .NET 4 series and ASP.NET MVC 2 series for other on-going blog series I’m working on. [In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu] ASP.NET MVC How to Localize an ASP.NET MVC Application: Michael Ceranski has a good blog post that describes how to localize ASP.NET MVC 2 applications. ASP.NET MVC with jTemplates Part 1 and Part 2: Steve Gentile has a nice two-part set of blog posts that demonstrate how to use the jTemplate and DataTable jQuery libraries to implement client-side data binding with ASP.NET MVC. CascadingDropDown jQuery Plugin for ASP.NET MVC: Raj Kaimal has a nice blog post that demonstrates how to implement a dynamically constructed cascading dropdownlist on the client using jQuery and ASP.NET MVC. How to Configure VS 2010 Code Coverage for ASP.NET MVC Unit Tests: Visual Studio enables you to calculate the “code coverage” of your unit tests.  This measures the percentage of code within your application that is exercised by your tests – and can give you a sense of how much test coverage you have.  Gunnar Peipman demonstrates how to configure this for ASP.NET MVC projects. Shrinkr URL Shortening Service Sample: A nice open source application and code sample built by Kazi Manzur that demonstrates how to implement a URL Shortening Services (like bit.ly) using ASP.NET MVC 2 and EF4.  More details here. Creating RSS Feeds in ASP.NET MVC: Damien Guard has a nice post that describes a cool new “FeedResult” class he created that makes it easy to publish and expose RSS feeds from within ASP.NET MVC sites. NoSQL with MongoDB, NoRM and ASP.NET MVC Part 1 and Part 2: Nice two-part blog series by Shiju Varghese on how to use MongoDB (a document database) with ASP.NET MVC.  If you are interested in document databases also make sure to check out the Raven DB project from Ayende. Using the FCKEditor with ASP.NET MVC: Quick blog post that describes how to use FCKEditor – an open source HTML Text Editor – with ASP.NET MVC. ASP.NET Replace Html.Encode Calls with the New HTML Encoding Syntax: Phil Haack has a good blog post that describes a useful way to quickly update your ASP.NET pages and ASP.NET MVC views to use the new <%: %> encoding syntax in ASP.NET 4.  I blogged about the new <%: %> syntax – it provides an easy and concise way to HTML encode content. Integrating Twitter into an ASP.NET Website using OAuth: Scott Mitchell has a nice article that describes how to take advantage of Twiter within an ASP.NET Website using the OAuth protocol – which is a simple, secure protocol for granting API access. Creating an ASP.NET report using VS 2010 Part 1, Part 2, and Part 3: Raj Kaimal has a nice three part set of blog posts that detail how to use SQL Server Reporting Services, ASP.NET 4 and VS 2010 to create a dynamic reporting solution. Three Hidden Extensibility Gems in ASP.NET 4: Phil Haack blogs about three obscure but useful extensibility points enabled with ASP.NET 4. .NET 4 Entity Framework 4 Video Series: Julie Lerman has a nice, free, 7-part video series on MSDN that walks through how to use the new EF4 capabilities with VS 2010 and .NET 4.  I’ll be covering EF4 in a blog series that I’m going to start shortly as well. Getting Lazy with System.Lazy: System.Lazy and System.Lazy<T> are new features in .NET 4 that provide a way to create objects that may need to perform time consuming operations and defer the execution of the operation until it is needed.  Derik Whittaker has a nice write-up that describes how to use it. LINQ to Twitter: Nifty open source library on Codeplex that enables you to use LINQ syntax to query Twitter. Visual Studio 2010 Using Intellitrace in VS 2010: Chris Koenig has a nice 10 minute video that demonstrates how to use the new Intellitrace features of VS 2010 to enable DVR playback of your debug sessions. Make the VS 2010 IDE Colors look like VS 2008: Scott Hanselman has a nice blog post that covers the Visual Studio Color Theme Editor extension – which allows you to customize the VS 2010 IDE however you want. How to understand your code using Dependency Graphs, Sequence Diagrams, and the Architecture Explorer: Jennifer Marsman has a nice blog post describes how to take advantage of some of the new architecture features within VS 2010 to quickly analyze applications and legacy code-bases. How to maintain control of your code using Layer Diagrams: Another great blog post by Jennifer Marsman that demonstrates how to setup a “layer diagram” within VS 2010 to enforce clean layering within your applications.  This enables you to enforce a compiler error if someone inadvertently violates a layer design rule. Collapse Selection in Solution Explorer Extension: Useful VS 2010 extension that enables you to quickly collapse “child nodes” within the Visual Studio Solution Explorer.  If you have deeply nested project structures this extension is useful. Silverlight and Windows Phone 7 Building a Simple Windows Phone 7 Application: A nice tutorial blog post that demonstrates how to take advantage of Expression Blend to create an animated Windows Phone 7 application. If you haven’t checked out my Windows Phone 7 Twitter Tutorial I also recommend reading that. Hope this helps, Scott P.S. If you haven’t already, check out this month’s "Find a Hoster” page on the www.asp.net website to learn about great (and very inexpensive) ASP.NET hosting offers.

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  • Agile Testing Days 2012 – Day 1 – The birth of the #unicorn…

    - by Chris George
    Still riding the high from the tutorial day, I arrived at the conference venue eager to get cracking with the days talks. The opening Keynote was “Disciplined Agile Delivery: The Foundation for Scaling Agile” presented by Scott Ambler. The general ideas behind the methodology such as not re-inventing the wheel, and being goal driven, not prescriptive in how you work certainly struck chords with how we are trying to work in my team. Scott made some interesting observations about how scrum is quite prescriptive and is this really agile? I agreed with quite a few of his points on how what works for one team may not work for another. How a team works should be driven by context and reflection, not process and prescription. However was somewhat dubious about some of the statistics he rolled out towards the end. However, out of this keynote was born something that was to transcend this one presentation. During the talk, Scott mentioned on more than one occasion “In the real world”, and at one point made reference to people living in the land of unicorns and rainbows. The challenge was then laid down on twitter for all speakers to include a unicorn in their presentations… and for the most part this happened! It became an identity for this years conference, and I’m sure something that any attendee will always associate with Agile Testing Days 2012! Following this keynote, I attended “Going agile with Automated GUI Testing – Some personal insights” by Jan Zdunek from codecentric on the vendor track. My speciality is test automation, and in particular GUI testing, so this drew me to this talk more than the others. Thankfully, it was made clear from the very start that this was not peddling any particular product (even though it was on the vendor track), and Jan faithfully stuck to that. Most of the content was not new to me, but it was really comforting to hear someone else with very similar experiences to my own. In particular, things like how GUI testing is hard and is not a silver bullet; how record & replay is NOT a good thing to do (which drew a somewhat inflammatory tweet from an automation company when I tweeted that!). Something that I have started hearing around the place, and has certainly been murmuring at work is to push more of the automation coding onto the developers. After all they are the coding experts. I agree with this to a degree, but I personally enjoy coding and find it very rewarding doing so, therefore I’d be reluctant to give it up. I think there are some better alternatives such as pairing with a developer. Lastly, Jan mentioned, almost in passing, that we should consider virtualisation for gui testing for covering configuration combinations. On my project we’ve been running our win32/.NET GUI tests in cloud virtualisation for a couple of years now… I really should write about that! After lunch the second keynote of the day was by Lisa Crispin and Janet Gregory,”Myths about Agile Testing, De-Bunked”. It started off well… with the two ladies donning Medusa style head bands whilst they disbanding several myths about agile testing! I got the impression that it was perhaps not as slick as they would have liked, but then Janet was suffering with a very sore throat so kept losing her voice. Nevertheless, the presentation was captivating, and they debunked several myths such as : “Testing is dead”, “Testers must write code”, “Agile teams always deliver faster”. I didn’t take many notes for this because it was being recorded, but unfortunately the recordings have not been posted yet so I’ll write more about this when they are. The TestLab was held during a somewhat free for all time during most of the afternoon. It looked intriguing and proved to be one of the surprising experiences of the conference for me. Run by James Lyndsay and Bart Knaack, it consisted of a number of ‘stations’ that offered different testing problems. I opted for testing a mathematical drawing app call Geogebra, the task being to pair up and exploratory test it. After an allotted time, we discussed issues we’d found and decided if we wanted to continue ‘playing’ to which we all agreed! It was fun! The last track talk of the day was “Developers Exploratory Testing – Raising the bar” by Sigge Birgisson. One of the teams at Red Gate have tried Dev or Team exploratory testing a couple of times, and I was really interested to go to the presentation that prompted that. I was not disappointed! Sigge gave a first class presentation, and not only explained what DET was all about, but also how to go about implementing it. Little tips like calling it a ‘workshop’ rather than ‘testing’ I can really see working! Monday evening saw the presentation of the award for the Most Influential Agile Testing Professional Person go to a much deserved Lisa Crispin. The evening was great, with acrobatics, magic and music. My Takeaway Triple from Day 1:  Some of the cool stuff that was suggested in the GUI Testing talk, we are already doing. I should write about that! Testing is not dead! Perhaps testing will become more of a skill than a specific role, but it is certainly not dead. Team/Developer exploratory testing… seems like a no-brainer assuming you have a team who is willing.  Day 2 – Coming soon…

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  • How SQL Server 2014 impacts Red Gate’s SQL Compare

    - by Michelle Taylor
    SQL Compare 10.7 successfully connects to SQL Server 2014, but it doesn’t yet cover the SQL Server 2014 features which would require us to make major changes to SQL Compare to support. In this post I’m going to talk about the SQL Server 2014 features we’ve already begun supporting, and which ones we’re working on for the next release of SQL Compare (v11). From SQL Compare’s perspective, the new memory-optimized table functionality (some might know it as ‘Hekaton’) has been the most important change. It can’t be described as its own object type, but the new functionality is split across two existing object types (three if you count indexes), as it also comes with native stored procedures and inline indexes. Along with connectivity support, the SQL Compare team has already implemented the first part of the puzzle – inline specification of indexes. These are essential for memory-optimized tables because it’s not possible to alter the memory optimized table’s structure, and so indexes can’t be added after the fact without dropping the table. Books Online  shows this in more detail in the table_index and column_index clauses of http://msdn.microsoft.com/en-us/library/ms174979(v=sql.120).aspx. SQL Compare 10.7 currently supports reading the new inline index specification from script folders and source control repositories, and will write out inline indexes where it’s necessary to do so (i.e. in UDDTs or when attempting to write projects compatible with the SSDT database project format). However, memory-optimized tables themselves are not yet supported in 10.7. The team is actively working on making them available in the v11 release with full support later in the year, and in a beta version before that. Fortunately, SQL Compare already has some ways of handling tables that have to be dropped and created rather than altered, which are being adapted to handle this new kind of table. Because it’s one of the largest new database engine features, there’s an equally large Books Online section on memory-optimized tables, but for us the most important parts of the documentation are the normal table features that are changed or unsupported and the new syntax found in the T-SQL reference pages. We are treating SQL Compare’s support of Natively Compiled Stored Procedures as a separate unit of work, which will be available in a subsequent beta and also feed into the v11 release. This new type of stored procedure is designed to work with memory-optimized tables to maintain the performance improvements gained by them – but you can still also access memory-optimized tables from normal stored procedures and ad-hoc queries. To us, they’re essentially a limited-syntax stored procedure with a few extra options in the create statement, embodied in the updated CREATE PROCEDURE documentation and with the detailed limitations. They should be easier to handle than memory-optimized tables simply because the handling of stored procedures is less sensitive to dropping the object than the handling of tables. However, both share an incompatibility with DDL triggers and Event Notifications which mean we’ll need to temporarily disable these during the specific deployment operations that involve them – don’t worry, we’ll supply a warning if this is the case so that you can check your auditing arrangements can handle the situation. There are also a handful of other improvements in SQL Server 2014 which affect SQL Compare and SQL Data Compare that are not connected to memory optimized tables. The largest of these are the improvements to columnstore indexes, with the capability to create clustered columnstore indexes and update columnstore tables through them – for more detail, take a look at the new syntax reference. There’s also a new index option for better compression of columnstores (COLUMNSTORE_ARCHIVE) and a new statistics option for incremental per-partition statistics, plus the 90 compatibility level is being retired. We’re planning to finish up these small clean-up features last, and be ready to release SQL Compare 11 with full SQL 2014 support early in Q3 this year. For a more thorough overview of what’s new in SQL Server 2014, Books Online’s What’s New section is a good place to start (although almost all the changes in this version are in the Database Engine).

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  • ADF Enterprise Application Development - Made Simple (Book Review)

    - by Frank Nimphius
      Sten E. Vesterli wrote the "Oracle ADF Enterprise Application Development – Made Simple" book published by Packt Publishing in 2011 http://www.packtpub.com/oracle-adf-enterprise-application-development/book A common question on OTN, but also when talking to clients or customers is about where and how to start your ADF application development. Especially when the current programming background is not in Java, but 4 GL or PLSQL, developers often look for answers to the following questions: · How long does it take to learn Oracle ADF ? · How long does it take to replace a Forms application with ADF ? · How many developers do I need? · Do I need to know Java to use ADF and if yes, how good do I need to know this? · How do I structure my programming files, organizing them in JDeveloper work spaces, projects and libraries? · What is best practices for naming Java packages and how to void naming conflicts in ADF in general? · How many Application Modules do I need or should I create? · How to test applications? Sten Vesterli answers all of the above questions and more in his book http://www.packtpub.com/oracle-adf-enterprise-application-development/book , which makes it great value add to the 3 existing Oracle ADF books. In order of complexity (which also is the order in which reading the available Oracle ADF books makes sense), in my opinion, Sten's book should come second – though it also is useful to those that are already more advanced with Oracle ADF. So if you are absolutely new to Oracle ADF, then the order of books to read to get you up on an expert level should be: 1. Grant Ronald; "Quick Start Guide to Oracle Fusion Development: Oracle JDeveloper and Oracle ADF" (McGraw Hill 2010) 2. Sten Vesterli; "Oracle ADF Enterprise Application Development – Made Simple" (Packt Publishing 2011) 3. Duncan Mills, Peter Koletzke; " Oracle JDeveloper 11g Handbook: A Guide to Fusion Web Development" (McGraw Hill 2009) 4. Frank Nimphius, Lynn Munsinger; " Oracle Fusion Developer Guide: Building Rich Internet Applications with Oracle ADF Business Components and Oracle ADF Faces" (McGraw Hill 2010) If you are not new to Oracle ADF and Orace JDeveloper, then buy Sten Vesterli's book anyway. It is worth it and you want to have it on your book shelf. See below the table of content to get a better idea of what this book covers: · Chapter 1: The ADF Proof of Concept · Chapter 2: Estimating the Effort · Chapter 3: Getting Organized · Chapter 4: Productive Teamwork · Chapter 5: Prepare to Build · Chapter 6: Building the Enterprise Application · Chapter 7: Testing your Application · Chapter 8: Look and Feel · Chapter 9: Customizing the Functionality · Chapter 10: Securing your ADF Application · Chapter 11: Package and Deliver · Appendix: Internationalization The book is written with a lot of good humor, which makes the read very enjoyable (from a geek's perspective, of course). My favorite quote – just in case you are interested - is from page 97, when Sten talks about getting organized: " Stop sending e-mails to your team. Just stop it. E-mail is so last century.…" So true, so true! This quote's runner up is the "boss key" on page 128 where Sten talks about productivity and how Oracle Team Productivity Center (TPC) can help you with this. Quotes like these stick to your brains and make sure you never forget. Go for it!

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  • Ok it has been pointed out to me

    - by Ratman21
    That it seems my blog is more of poor me or pity me or I deserve a job blog.   Hmmm I wont say, I have not wined here as I have used this blog to vent my frustration on the whole out of work thing (lack of money, self worth, family issues and the never end bills coming my way) but, it was also me trying to reach to others in the same boat as well as advertising, hay I am out here, employers.   It was also said, that I don’t have any thing listed here on me, like a cover letter or resume. Well there is but, it was so many months and post ago. Also what I had posted is not current. So here is my most current cover and resume.   Scott L Newman 45219 Dutton Way Callahan, Fl. 32011 To Whom It May Concern: I am really interested in the IT vacancie that you have listed for your company. Maybe I don’t have all the qualifications you want (hold on don’t hit delete yet) yet! But maybe I do, as I have over 20 + years experience in "IT” RIGHT NOW.   Read the rest of my cover and my resume. You will see what my “IT” skills are and it will Show that I can to this work! I can bring to your company along with my, can do attitude, a broad range of skills, including: Certified CompTIA A+, Security+  and Network+ Technician §         2.5 years (NOC) Network experience on large Cisco based Wan – UK to Austria §         20 years experience MIS/DP – Yes I can do IBM mainframes and Tandem  non-stops too §         18 years experience as technical Help Desk support – panicking users, no problem §         18 years experience with PC/Server based system, intranet and internet systems §         10+ years experienced on: Microsoft Office, Windows XP and Data Network Fundamentals (YES I do windows) §         Strong trouble shooting skills for software, hard ware and circuit issues (and I can tell you what kind of horrors I had to face on all of them). §         Very experienced on working with customers on problems – again panicking users, no problem §         Working experience with Remote Access (VPN/SecurID) – I didn’t just study them I worked on/with them §         Skilled in getting info for and creating documentation for Operation procedures (I don’t just wait for them to give it to me I go out and get it. Waiting for info on working applications is, well dumb) Multiple software languages (Hey I have done some programming) And much more experiences in “IT” (Mortgage, stocks and financial information systems experience and have worked “IT” in a hospital) Can multitask, also have ability to adapt to change and learn quickly. (once was put in charge of a system that I had not worked with for over two years. Talk about having to relearn and adapt to changes but, I did it.) I would welcome the opportunity to further discuss this position with you. If you have questions or would like to schedule an interview, please contact me by phone at 904-879-4880 or on my cell 352-356-0945 or by e-mail at [email protected] or leave a message on my web site (http://beingscottnewman.webs.com/). I have enclosed/attached my resume for your review and I look forward to hearing from you.   Thank you for taking a moment to consider my cover letter and resume. I appreciate how busy you are. Sincerely, Scott L. Newman    Scott L. Newman 45219 Dutton Way, Callahan, FL 32011? H (904)879-4880 C (352)356-0945 ? [email protected] Web - http://beingscottnewman.webs.com/                                                       ______                                                                                       OBJECTIVE To obtain a Network Operation or Helpdesk position.     PROFILE Information Technology Professional with 20+ years of experience. Volunteer website creator and back-up sound technician at True Faith Christian Fellowship. CompTIA A+, Network+ and Security+ Certified.   TECHNICAL AND PROFESSIONAL SKILLS   §         Technical Support §         Frame Relay §         Microsoft Office Suite §         Inventory Management §         ISDN §         Windows NT/98/XP §         Client/Vendor Relations §         CICS §         Cisco Routers/Switches §         Networking/Administration §         RPG §         Helpdesk §         Website Design/Dev./Management §         Assembler §         Visio §         Programming §         COBOL IV §               EDUCATION ? New HorizonsComputerLearningCenter, Jacksonville, Florida – CompTIA A+, Security+ and Network+ Certified.             Currently working on CCNA Certification ?MottCommunity College, Flint, Michigan – Associates Degree - Data Processing and General Education ? Currently studying Japanese     PROFESSIONAL             TrueFaithChristianFellowshipChurch – Callahan, FL, October 2009 – Present Web site Tech ·        Web site Creator/tech, back up song leader and back up sound technician. Note church web site is (http://ambassadorsforjesuschrist.webs.com/) U.S. Census (temp employee) Feb. 23 to March 8, 2010 ·        Enumerator for NassauCounty   ThomasCreekBaptistChurch – Callahan, FL,     June 2008 – September 2009 Churchsound and video technician      ·        sound and video technician           Fidelity National Information Services ? Jacksonville, FL ? February 01, 2005 to October 28, 2008 Client Server Dev/Analyst I ·        Monitored Multiple Debit Card sites, Check Authorization customers and the Card Auth system (AuthNet) for problems with the sites, connections, servers (on our LAN) and/or applications ·        Night (NOC) Network operator for a large Wide Area Network (WAN) ·        Monitored Multiple Check Authorization customers for problems with circuits, routers and applications ·        Resolved circuit and/or router issues or assist circuit carrier in resolving issue ·        Resolved application problems or assist application support in resolution ·        Liaison between customer and application support ·        Maintained and updated the NetOps Operation procedures Guide ·        Kept the listing of equipment on the raised floor updated ·        Involved in the training of all Night Check and Card server operation operators ·        FNIS acquired Certegy in 2005. Was one of 3 kept on.   Certegy ? St.Pete, FL ? August 31, 2003 to February 1, 2005 Senior NetOps Operator(FNIS acquired Certegy in 2005 all of above jobs/skills were same as listed in FNIS) ·        Converting Documentation to Adobe format ·        Sole trainer of day/night shift System Management Center operators (SMC) ·        Equifax spun off Card/Check Dept. as Certegy. Certegy terminated contract with EDS. One of six in the whole IT dept that was kept on.   EDS  (Certegy Account) ? St.Pete, FL ? July 1, 1999 to August 31, 2003 Senior NetOps Operator ·        Equifax outsourced the NetOps dept. to EDS in 1999. ·        Same job skills as listed above for FNIS.   Equifax ? St.Pete&Tampa, FL ? January 1, 1991 to July 1, 1999 NetOps/Tandem Operator ·        All of the above for FNIS, except for circuit and router issues ·        Operated, monitored and trouble shot Tandem mainframe and servers on LAN ·        Supported in the operation of the Print, Tape and Microfiche rooms ·        Equifax acquired TelaCredit in 1991.   TelaCredit ? Tampa, FL ? June 28, 1989 to January 1, 1991 Tandem Operator ·        Operated and monitored Tandem Non-stop systems for Card and Check Auths ·        Operated multiple high-speed Laser printers and Microfiche printers ·        Mounted, filed and maintained 18 reel-to-reel mainframe tape drives, cartridges tape drives and tape library.

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  • Best ways to teach a beginner to program?

    - by Justin Standard
    Original Question I am currently engaged in teaching my brother to program. He is a total beginner, but very smart. (And he actually wants to learn). I've noticed that some of our sessions have gotten bogged down in minor details, and I don't feel I've been very organized. (But the answers to this post have helped a lot.) What can I do better to teach him effectively? Is there a logical order that I can use to run through concept by concept? Are there complexities I should avoid till later? The language we are working with is Python, but advice in any language is welcome. How to Help If you have good ones please add the following in your answer: Beginner Exercises and Project Ideas Resources for teaching beginners Screencasts / blog posts / free e-books Print books that are good for beginners Please describe the resource with a link to it so I can take a look. I want everyone to know that I have definitely been using some of these ideas. Your submissions will be aggregated in this post. Online Resources for teaching beginners: A Gentle Introduction to Programming Using Python How to Think Like a Computer Scientist Alice: a 3d program for beginners Scratch (A system to develop programming skills) How To Design Programs Structure and Interpretation of Computer Programs Learn To Program Robert Read's How To Be a Programmer Microsoft XNA Spawning the Next Generation of Hackers COMP1917 Higher Computing lectures by Richard Buckland (requires iTunes) Dive into Python Python Wikibook Project Euler - sample problems (mostly mathematical) pygame - an easy python library for creating games Create Your Own Games With Python ebook Foundations of Programming for a next step beyond basics. Squeak by Example Recommended Print Books for teaching beginners Accelerated C++ Python Programming for the Absolute Beginner Code by Charles Petzold

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  • Nested Routes and Parameters for Rails URLs (Best Practice)

    - by viatropos
    Hey there, I have a decent understanding of RESTful urls and all the theory behind not nesting urls, but I'm still not quite sure how this looks in an enterprise application, like something like Amazon, StackOverflow, or Google... Google has urls like this: http://code.google.com/apis/ajax/ http://code.google.com/apis/maps/documentation/staticmaps/ https://www.google.com/calendar/render?tab=mc Amazon like this: http://www.amazon.com/books-used-books-textbooks/b/ref=sa_menu_bo0?ie=UTF8&node=283155&pf_rd_p=328655101&pf_rd_s=left-nav-1&pf_rd_t=101&pf_rd_i=507846&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1PK4ZKN4YWJJ9B86ANC9 http://www.amazon.com/Ruby-Programming-Language-David-Flanagan/dp/0596516177/ref=sr_1_1?ie=UTF8&s=books&qid=1258755625&sr=1-1 And StackOverflow like this: http://stackoverflow.com/users/169992/viatropos http://stackoverflow.com/questions/tagged/html http://stackoverflow.com/questions/tagged?tagnames=html&sort=newest&pagesize=15 So my question is, what is best practice in terms of creating urls for systems like these? When do you start storing parameters in the url, when don't you? These big companies don't seem to be following the rules so hotly debated in the ruby community (that you should almost never nest URLs for example), so I'm wondering how you go about implementing your own urls in larger scale projects because it seems like the idea of not nesting urls breaks down at anything larger than a blog. Any tips?

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  • please clarify some aspects of AJAX with ASP.NET web forms for a beginner

    - by citrus
    Im familiar with asp.net web forms. I would now like to move on to writing web applications that use AJAX. I would like to get to the stage where I can create an app: that has "edit in place" (no page reload) where i can reorder images using drag and drop (also saves the order to DB) that has google like search suggestions while typing on the fly 1)So do I need to learn how to use AJAX.net and Jquery(my JS library of choice)? Can I make do using only AJAX.net or only Jquery? 2)As far a I know, Jquery will allow me to perform client side manipulations/actions and AJAX.net is the part that will allow me to connect some of my actions to the Server. EG. if I wanted to re-order elements using drag and drop, I would use Jquery, but in order to save the result of the re-order to the DB I would have to use AJAX.net correct? 2a)So In order to learn how to do the above Im thinking I should first learn Jquery so I know how to manipulate/ select elements, and then I can lean how to save these changes to the DB. 3)I searched the books titled "ASP.net AJAX in action" and ASP.net 3.5 AJAX, both of these books did not contain any references to "Jquery". Is this because they may be using a different JS library, or perhaps the book focuses on the AJAX user controls? I just found it confusing that 2 popular AJAX books dont make any reference to Jquery. Thanks for any help.

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  • Collaborative filtering in MySQL ?

    - by user281434
    Hi I'm trying to develop a site that recommends items(fx. books) to users based on their preferences. So far, I've read O'Reilly's "Collective Intelligence" and numerous other online articles. They all, however, seem to deal with single instances of recommendation, for example if you like book A then you might like book B. What I'm trying to do is to create a set of 'preference-nodes' for each user on my site. Let's say a user likes book A,B and C. Then, when they add book D, I don't want the system to recommend other books based solely other users experience with book D. I wan't the system to look up similar 'preference-nodes' and recommend books based on that. Here's an example of 4 nodes: User1: 'book A'->'book B'->'book C' User2: 'book A'->'book B'->'book C'->'book D' user3: 'book X'->'book Y'->'book C'->'book Z' user4: 'book W'->'book Q'->'book C'->'book Z' So a recommendation system, as described in the material I've read, would recommend book Z to User 1, because there are two people who recommends Z in conjuction with liking C (ie. Z weighs more than D), even though a user with a similar 'preference-node', User2, would be more qualified to recommend book D because he has a more similar interest-pattern. So does any of you have any experience with this sort of thing? Is there some things I should try to read or does there exist any open source systems for this? Thanks for your time! Small edit: I think last.fm's algorithm is doing exactly what I my system to do. Using the preference-trees of people to recommmend music more personally to people. Instead of just saying "you might like B because you liked A"

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  • Importing fixtures with foreign keys and SQLAlchemy?

    - by Chris Reid
    I've been experimenting with using fixture to load test data sets into my Pylons / PostgreSQL app. This works great except that it fails to properly create foreign keys if they reference an auto increment id field. My fixture looks like this: class AuthorsData(DataSet): class frank_herbert: first_name = "Frank" last_name = "Herbert" class BooksData(DataSet): class dune: title = "Dune" author_id = AuthorsData.frank_herbert.ref('id') And the model: t_authors = sa.Table("authors", meta.metadata, sa.Column("id", sa.types.Integer, primary_key=True), sa.Column("first_name", sa.types.String(100)), sa.Column("last_name", sa.types.String(100)), ) t_books = sa.Table("books", meta.metadata, sa.Column("id", sa.types.Integer, primary_key=True), sa.Column("title", sa.types.String(100)), sa.Column("author_id", sa.types.Integer, sa.ForeignKey('authors.id')) ) When running "paster setup-app development.ini", SQLAlchemey reports the FK value as "None" so it's obviously not finding it: 15:59:48,683 INFO [sqlalchemy.engine.base.Engine.0x...9eb0] INSERT INTO books (title, author_id) VALUES (%(title)s, %(author_id)s) RETURNING books.id 15:59:48,683 INFO [sqlalchemy.engine.base.Engine.0x...9eb0] {'author_id': None, 'title': 'Dune'} The fixture docs actually warn that this might be a problem: "However, in some cases you may need to reference an attribute that does not have a value until it is loaded, like a serial ID column. (Note that this is not supported by the SQLAlchemy data layer when using sessions.)" http://farmdev.com/projects/fixture/using-dataset.html#referencing-foreign-dataset-classes Does this mean that this is just not supported with SQLAlchemy? Or is it possible to load the data without using SA "sessions"? How are other people handling this issue?

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  • Creating dynamic jQuery tooltips for dynamic content

    - by Mel
    I'm using the qTip jQuery plugin to create tooltips for a set of links. Two problems: How do I create a set of tooltips for three dynamically generated links where the content of the tooltip will also be dynamic: a href="books.cfm?bookID=11"Book One a href="books.cfm?bookID=22"Book Two a href="books.cfm?bookID=33"Book Three I would like to create a tooltip for each link. Each tooltip will then load details about each book. Thus I must pass the bookID to the tooltip: $('#catalog a[href]').each(function() { $(this).qtip( { content: { URL: 'cfcs/viewbooks.cfc?method=bookDetails', data: { bookID: <cfoutput>#indexView.bookID#</cfoutput> }, method: 'get' } }); }); Unfortunately the above code is not working correctly. I've gotten it to work when I've used a static 'bookID' instead of a dynamically generated number. Even when it does work (by using a static number for 'bookID', I can't format the data correctly. It comes back as a query result, or a bunch of text strings. Should I send back the results as HTML? Unsure. PS: I am an absolute NOVICE to Javascript and jQuery, so please try not to be as technical. Many thanks!

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  • How to wrtie a XML License Line(ended with a forward slash '/') in C#?

    - by Nano HE
    I want to write a XML file as below: <?xml version="1.0" encoding="UTF-8"?> <books xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <License licenseId="" licensePath="" /> Some piece of my code attached here // Create a new file in D:\\ and set the encoding to UTF-8 XmlTextWriter textWriter = new XmlTextWriter("D:\\books.xml", System.Text.Encoding.UTF8); // Format automatically textWriter.Formatting = Formatting.Indented; // Opens the document textWriter.WriteStartDocument(); // Write the namespace declaration. textWriter.WriteStartElement("books", null); // Write the genre attribute. textWriter.WriteAttributeString("xmlns", "xsd", null, "http://www.w3.org/2001/XMLSchema"); textWriter.WriteAttributeString("xmlns", "xsi", null, "http://www.w3.org/2001/XMLSchema-instance"); And now I need to write the License Line below in C# <License licenseId="" licensePath="" /> But I don't know how to move on for I found the Line ended with the forward slash / .Thank you.

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  • Java split giving opposite order of arabic characters

    - by MuhammadA
    I am splitting the following string using \\| in java (android) using the IntelliJ 12 IDE. Everything is fine except the last part, somehow the split picks them up in the opposite order : As you can see the real positioning 34,35,36 is correct and according to the string, but when it gets picked out into split part no 5 its in the wrong order, 36,35,34 ... Any way I can get them to be in the right order? My Code: public ArrayList<Book> getBooksFromDatFile(Context context, String fileName) { ArrayList<Book> books = new ArrayList<Book>(); try { // load csv from assets InputStream is = context.getAssets().open(fileName); try { BufferedReader reader = new BufferedReader(new InputStreamReader(is)); String line; while ((line = reader.readLine()) != null) { String[] RowData = line.split("\\|"); books.add(new Book(RowData[0], RowData[1], RowData[2], RowData[3], RowData[4], RowData[5])); } } catch (IOException ex) { Log.e(TAG, "Error parsing csv file!"); } finally { try { is.close(); } catch (IOException e) { Log.e(TAG, "Error closing input stream!"); } } } catch (IOException ex) { Log.e(TAG, "Error reading .dat file from assets!"); } return books; }

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  • What's the best way to learn .NET?

    - by duffymo
    I've been developing Java EE for quite a while now. I've used WebLogic, Tomcat, Spring, and Hibernate extensively, so I have a mental model of what features are available and how things are developed and deployed. The problem that I have with .NET is that I don't have a clear mapping of its features onto Java EE. Here's what I know so far: Java EE - .NET Java - C# JAR - DLL WAR - ? (deployment in general) EAR - ? (deployment in general) Tomcat - IIS web server JSP - ASP? JDBC - ODBC JMS - MSMQ JTA - Microsoft Transaction Manager So much of the functionality that WebLogic handles appears to be dispersed throughout the Windows OS. My confusion kicks in when I see the waves of books at Borders - VB.NET, ASP.NET, C#, etc. If I'm not a VB programmer, would it be possible to stick with C# and write enterprise apps that are the equivalent of what I'm used to with Java EE? If there were a Top Three list of books to learn from, what would they be? The "Head First" series has certainly been successful for Java. http://www.amazon.com/Head-First-C-Brain-Friendly-Guides/dp/0596514824/ref=sr_1_1?ie=UTF8&s=books&qid=1224121193&sr=8-1 Equally well recommended for .NET learning? Thanks. - %

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  • I want to request JSON inside of a WordPress page.

    - by gnucom
    Hello Everyone, For the last few hours I've been trying to set up this http://code.google.com/apis/books/docs/dynamic-links.html on a WordPress blog. Google's API sends back a JSON response (which is supposed to be "put" into _GBSBookInfo variable). However, that variable never is assigned so my javascript callback function explodes saying the variable doesn't exist. So far, all of my javascript is in the WordPress header. I tried this outside of WordPress and it works fine. This is the static page: <script src="http://books.google.com/books?bibkeys=0307346609&jscmd=viewapi&callback=response_handler"> This is the handler: function response_handler(data) { var bookInfo = _GBSBookInfo["0307346609"]; // the var that doesn't exist document.getElementById("test123").innerHTML = bookInfo.thumbnail_url; } Thanks for any help in advance, WordPress has been extremely frustrating by limiting so much! If I'm doing anything stupid please say so, I'm a new javascript programmer. EDIT: I've used firebug so far to identify the problem to be: the _GBSBookInfo variable never gets "created" or "exists". I'm not sure how javascript works at this level. Hopefully this helps. ERRORS: Error: _GBSBookInfo is not defined Line: 79

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  • Can I make an identity field span multiple tables in SQL Server?

    - by johnnycakes
    Can I have an "identity" (unique, non-repeating) column span multiple tables? For example, let's say I have two tables: Books and Authors. Authors AuthorID AuthorName Books BookID BookTitle The BookID column and the AuthorID column are identity columns. I want the identity part to span both columns. So, if there is an AuthorID with a value of 123, then there cannot be a BookID with a value of 123. And vice versa. I hope that makes sense. Is this possible? Thanks. Why do I want to do this? I am writing an APS.NET MVC app. I am creating a comment section. Authors can have comments. Books can have comments. I want to be able to pass an entity ID (a book ID or an author ID) to an action and have the action pull up all the corresponding comments. The action won't care if it's a book or an author or whatever. Sound reasonable?

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  • Programming logic best practice - redundant checks

    - by eldblz
    I'm creating a large PHP project and I've a trivial doubt about how to proceed. Assume we got a class books, in this class I've the method ReturnInfo: function ReturnInfo($id) { if( is_numeric($id) ) { $query = "SELECT * FROM books WHERE id='" . $id . "' LIMIT 1;"; if( $row = $this->DBDrive->ExecuteQuery($query, $FetchResults=TRUE) ) { return $row; } else { return FALSE; } } else { throw new Exception('Books - ReturnInfo - id not valid.'); } } Then i have another method PrintInfo function PrintInfo($id) { print_r( $this->ReturnInfo($id) ); } Obviously the code sample are just for example and not actual production code. In the second method should I check (again) if id is numeric ? Or can I skip it because is already taken care in the first method and if it's not an exception will be thrown? Till now I always wrote code with redundant checks (no matter if already checked elsewhere i'll check it also here) Is there a best practice? Is just common sense? Thank you in advance for your kind replies.

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  • How can I work out if a date is on or before today?

    - by Yvonne
    My web application consists of library type system where books have due dates. I have the current date displayed on my page, simply by using this: date_default_timezone_set('Europe/London'); $date = date; print $date("d/m/Y"); I have set 'date' as a variable because I'm not sure if it makes a difference when I use it in the IF statement you're about see, on my library books page. On this page, I am simply outputting the due dates of the books, many have dates which have not yet reached todays date, and others which have dates greater than todays date. Basically, all I want is the due date to appear bold (or strong), if it has passed todays date (the system displayed date). This is what I have and thought would work: <? if ($duedate < $date) { echo '<td><strong>'; } else { echo '<td>'; } ?> <?php echo $date('d/m/Y', $timestamp);?></strong></td> I have declared $timestamp as a var which converts the date of default MySQL format to a UK version. Can anyone help me out? I thought this would've been very straight forward!

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  • [Ruby On Rails] belongs_to with :class_name option fails.

    - by crackpot
    I have no idea what went wrong but I can't get belongs_to work with :class_name option. Could somebody enlighten me. Thanks a lot! Here is a snip from my code. class CreateUsers < ActiveRecord::Migration def self.up create_table :users do |t| t.text :name end end def self.down drop_table :users end end ##################################################### class CreateBooks < ActiveRecord::Migration def self.up create_table :books do |t| t.text :title t.integer :author_id, :null => false end end def self.down drop_table :books end end ##################################################### class User < ActiveRecord::Base has_many: books end ##################################################### class Book < ActiveRecord::Base belongs_to :author, :class_name => 'User', :validate => true end ##################################################### class BooksController < ApplicationController def create user = User.new({:name => 'John Woo'}) user.save @failed_book = Book.new({:title => 'Failed!', :author => @user}) @failed_book.save # missing author_id @success_book = Book.new({:title => 'Nice day', :author_id => @user.id}) @success_book.save # no error! end end environment: ruby 1.9.1-p387 Rails 2.3.5

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  • A Taxonomy of Numerical Methods v1

    - by JoshReuben
    Numerical Analysis – When, What, (but not how) Once you understand the Math & know C++, Numerical Methods are basically blocks of iterative & conditional math code. I found the real trick was seeing the forest for the trees – knowing which method to use for which situation. Its pretty easy to get lost in the details – so I’ve tried to organize these methods in a way that I can quickly look this up. I’ve included links to detailed explanations and to C++ code examples. I’ve tried to classify Numerical methods in the following broad categories: Solving Systems of Linear Equations Solving Non-Linear Equations Iteratively Interpolation Curve Fitting Optimization Numerical Differentiation & Integration Solving ODEs Boundary Problems Solving EigenValue problems Enjoy – I did ! Solving Systems of Linear Equations Overview Solve sets of algebraic equations with x unknowns The set is commonly in matrix form Gauss-Jordan Elimination http://en.wikipedia.org/wiki/Gauss%E2%80%93Jordan_elimination C++: http://www.codekeep.net/snippets/623f1923-e03c-4636-8c92-c9dc7aa0d3c0.aspx Produces solution of the equations & the coefficient matrix Efficient, stable 2 steps: · Forward Elimination – matrix decomposition: reduce set to triangular form (0s below the diagonal) or row echelon form. If degenerate, then there is no solution · Backward Elimination –write the original matrix as the product of ints inverse matrix & its reduced row-echelon matrix à reduce set to row canonical form & use back-substitution to find the solution to the set Elementary ops for matrix decomposition: · Row multiplication · Row switching · Add multiples of rows to other rows Use pivoting to ensure rows are ordered for achieving triangular form LU Decomposition http://en.wikipedia.org/wiki/LU_decomposition C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-lu-decomposition-for-solving.html Represent the matrix as a product of lower & upper triangular matrices A modified version of GJ Elimination Advantage – can easily apply forward & backward elimination to solve triangular matrices Techniques: · Doolittle Method – sets the L matrix diagonal to unity · Crout Method - sets the U matrix diagonal to unity Note: both the L & U matrices share the same unity diagonal & can be stored compactly in the same matrix Gauss-Seidel Iteration http://en.wikipedia.org/wiki/Gauss%E2%80%93Seidel_method C++: http://www.nr.com/forum/showthread.php?t=722 Transform the linear set of equations into a single equation & then use numerical integration (as integration formulas have Sums, it is implemented iteratively). an optimization of Gauss-Jacobi: 1.5 times faster, requires 0.25 iterations to achieve the same tolerance Solving Non-Linear Equations Iteratively find roots of polynomials – there may be 0, 1 or n solutions for an n order polynomial use iterative techniques Iterative methods · used when there are no known analytical techniques · Requires set functions to be continuous & differentiable · Requires an initial seed value – choice is critical to convergence à conduct multiple runs with different starting points & then select best result · Systematic - iterate until diminishing returns, tolerance or max iteration conditions are met · bracketing techniques will always yield convergent solutions, non-bracketing methods may fail to converge Incremental method if a nonlinear function has opposite signs at 2 ends of a small interval x1 & x2, then there is likely to be a solution in their interval – solutions are detected by evaluating a function over interval steps, for a change in sign, adjusting the step size dynamically. Limitations – can miss closely spaced solutions in large intervals, cannot detect degenerate (coinciding) solutions, limited to functions that cross the x-axis, gives false positives for singularities Fixed point method http://en.wikipedia.org/wiki/Fixed-point_iteration C++: http://books.google.co.il/books?id=weYj75E_t6MC&pg=PA79&lpg=PA79&dq=fixed+point+method++c%2B%2B&source=bl&ots=LQ-5P_taoC&sig=lENUUIYBK53tZtTwNfHLy5PEWDk&hl=en&sa=X&ei=wezDUPW1J5DptQaMsIHQCw&redir_esc=y#v=onepage&q=fixed%20point%20method%20%20c%2B%2B&f=false Algebraically rearrange a solution to isolate a variable then apply incremental method Bisection method http://en.wikipedia.org/wiki/Bisection_method C++: http://numericalcomputing.wordpress.com/category/algorithms/ Bracketed - Select an initial interval, keep bisecting it ad midpoint into sub-intervals and then apply incremental method on smaller & smaller intervals – zoom in Adv: unaffected by function gradient à reliable Disadv: slow convergence False Position Method http://en.wikipedia.org/wiki/False_position_method C++: http://www.dreamincode.net/forums/topic/126100-bisection-and-false-position-methods/ Bracketed - Select an initial interval , & use the relative value of function at interval end points to select next sub-intervals (estimate how far between the end points the solution might be & subdivide based on this) Newton-Raphson method http://en.wikipedia.org/wiki/Newton's_method C++: http://www-users.cselabs.umn.edu/classes/Summer-2012/csci1113/index.php?page=./newt3 Also known as Newton's method Convenient, efficient Not bracketed – only a single initial guess is required to start iteration – requires an analytical expression for the first derivative of the function as input. Evaluates the function & its derivative at each step. Can be extended to the Newton MutiRoot method for solving multiple roots Can be easily applied to an of n-coupled set of non-linear equations – conduct a Taylor Series expansion of a function, dropping terms of order n, rewrite as a Jacobian matrix of PDs & convert to simultaneous linear equations !!! Secant Method http://en.wikipedia.org/wiki/Secant_method C++: http://forum.vcoderz.com/showthread.php?p=205230 Unlike N-R, can estimate first derivative from an initial interval (does not require root to be bracketed) instead of inputting it Since derivative is approximated, may converge slower. Is fast in practice as it does not have to evaluate the derivative at each step. Similar implementation to False Positive method Birge-Vieta Method http://mat.iitm.ac.in/home/sryedida/public_html/caimna/transcendental/polynomial%20methods/bv%20method.html C++: http://books.google.co.il/books?id=cL1boM2uyQwC&pg=SA3-PA51&lpg=SA3-PA51&dq=Birge-Vieta+Method+c%2B%2B&source=bl&ots=QZmnDTK3rC&sig=BPNcHHbpR_DKVoZXrLi4nVXD-gg&hl=en&sa=X&ei=R-_DUK2iNIjzsgbE5ID4Dg&redir_esc=y#v=onepage&q=Birge-Vieta%20Method%20c%2B%2B&f=false combines Horner's method of polynomial evaluation (transforming into lesser degree polynomials that are more computationally efficient to process) with Newton-Raphson to provide a computational speed-up Interpolation Overview Construct new data points for as close as possible fit within range of a discrete set of known points (that were obtained via sampling, experimentation) Use Taylor Series Expansion of a function f(x) around a specific value for x Linear Interpolation http://en.wikipedia.org/wiki/Linear_interpolation C++: http://www.hamaluik.com/?p=289 Straight line between 2 points à concatenate interpolants between each pair of data points Bilinear Interpolation http://en.wikipedia.org/wiki/Bilinear_interpolation C++: http://supercomputingblog.com/graphics/coding-bilinear-interpolation/2/ Extension of the linear function for interpolating functions of 2 variables – perform linear interpolation first in 1 direction, then in another. Used in image processing – e.g. texture mapping filter. Uses 4 vertices to interpolate a value within a unit cell. Lagrange Interpolation http://en.wikipedia.org/wiki/Lagrange_polynomial C++: http://www.codecogs.com/code/maths/approximation/interpolation/lagrange.php For polynomials Requires recomputation for all terms for each distinct x value – can only be applied for small number of nodes Numerically unstable Barycentric Interpolation http://epubs.siam.org/doi/pdf/10.1137/S0036144502417715 C++: http://www.gamedev.net/topic/621445-barycentric-coordinates-c-code-check/ Rearrange the terms in the equation of the Legrange interpolation by defining weight functions that are independent of the interpolated value of x Newton Divided Difference Interpolation http://en.wikipedia.org/wiki/Newton_polynomial C++: http://jee-appy.blogspot.co.il/2011/12/newton-divided-difference-interpolation.html Hermite Divided Differences: Interpolation polynomial approximation for a given set of data points in the NR form - divided differences are used to approximately calculate the various differences. For a given set of 3 data points , fit a quadratic interpolant through the data Bracketed functions allow Newton divided differences to be calculated recursively Difference table Cubic Spline Interpolation http://en.wikipedia.org/wiki/Spline_interpolation C++: https://www.marcusbannerman.co.uk/index.php/home/latestarticles/42-articles/96-cubic-spline-class.html Spline is a piecewise polynomial Provides smoothness – for interpolations with significantly varying data Use weighted coefficients to bend the function to be smooth & its 1st & 2nd derivatives are continuous through the edge points in the interval Curve Fitting A generalization of interpolating whereby given data points may contain noise à the curve does not necessarily pass through all the points Least Squares Fit http://en.wikipedia.org/wiki/Least_squares C++: http://www.ccas.ru/mmes/educat/lab04k/02/least-squares.c Residual – difference between observed value & expected value Model function is often chosen as a linear combination of the specified functions Determines: A) The model instance in which the sum of squared residuals has the least value B) param values for which model best fits data Straight Line Fit Linear correlation between independent variable and dependent variable Linear Regression http://en.wikipedia.org/wiki/Linear_regression C++: http://www.oocities.org/david_swaim/cpp/linregc.htm Special case of statistically exact extrapolation Leverage least squares Given a basis function, the sum of the residuals is determined and the corresponding gradient equation is expressed as a set of normal linear equations in matrix form that can be solved (e.g. using LU Decomposition) Can be weighted - Drop the assumption that all errors have the same significance –-> confidence of accuracy is different for each data point. Fit the function closer to points with higher weights Polynomial Fit - use a polynomial basis function Moving Average http://en.wikipedia.org/wiki/Moving_average C++: http://www.codeproject.com/Articles/17860/A-Simple-Moving-Average-Algorithm Used for smoothing (cancel fluctuations to highlight longer-term trends & cycles), time series data analysis, signal processing filters Replace each data point with average of neighbors. Can be simple (SMA), weighted (WMA), exponential (EMA). Lags behind latest data points – extra weight can be given to more recent data points. Weights can decrease arithmetically or exponentially according to distance from point. Parameters: smoothing factor, period, weight basis Optimization Overview Given function with multiple variables, find Min (or max by minimizing –f(x)) Iterative approach Efficient, but not necessarily reliable Conditions: noisy data, constraints, non-linear models Detection via sign of first derivative - Derivative of saddle points will be 0 Local minima Bisection method Similar method for finding a root for a non-linear equation Start with an interval that contains a minimum Golden Search method http://en.wikipedia.org/wiki/Golden_section_search C++: http://www.codecogs.com/code/maths/optimization/golden.php Bisect intervals according to golden ratio 0.618.. Achieves reduction by evaluating a single function instead of 2 Newton-Raphson Method Brent method http://en.wikipedia.org/wiki/Brent's_method C++: http://people.sc.fsu.edu/~jburkardt/cpp_src/brent/brent.cpp Based on quadratic or parabolic interpolation – if the function is smooth & parabolic near to the minimum, then a parabola fitted through any 3 points should approximate the minima – fails when the 3 points are collinear , in which case the denominator is 0 Simplex Method http://en.wikipedia.org/wiki/Simplex_algorithm C++: http://www.codeguru.com/cpp/article.php/c17505/Simplex-Optimization-Algorithm-and-Implemetation-in-C-Programming.htm Find the global minima of any multi-variable function Direct search – no derivatives required At each step it maintains a non-degenerative simplex – a convex hull of n+1 vertices. Obtains the minimum for a function with n variables by evaluating the function at n-1 points, iteratively replacing the point of worst result with the point of best result, shrinking the multidimensional simplex around the best point. Point replacement involves expanding & contracting the simplex near the worst value point to determine a better replacement point Oscillation can be avoided by choosing the 2nd worst result Restart if it gets stuck Parameters: contraction & expansion factors Simulated Annealing http://en.wikipedia.org/wiki/Simulated_annealing C++: http://code.google.com/p/cppsimulatedannealing/ Analogy to heating & cooling metal to strengthen its structure Stochastic method – apply random permutation search for global minima - Avoid entrapment in local minima via hill climbing Heating schedule - Annealing schedule params: temperature, iterations at each temp, temperature delta Cooling schedule – can be linear, step-wise or exponential Differential Evolution http://en.wikipedia.org/wiki/Differential_evolution C++: http://www.amichel.com/de/doc/html/ More advanced stochastic methods analogous to biological processes: Genetic algorithms, evolution strategies Parallel direct search method against multiple discrete or continuous variables Initial population of variable vectors chosen randomly – if weighted difference vector of 2 vectors yields a lower objective function value then it replaces the comparison vector Many params: #parents, #variables, step size, crossover constant etc Convergence is slow – many more function evaluations than simulated annealing Numerical Differentiation Overview 2 approaches to finite difference methods: · A) approximate function via polynomial interpolation then differentiate · B) Taylor series approximation – additionally provides error estimate Finite Difference methods http://en.wikipedia.org/wiki/Finite_difference_method C++: http://www.wpi.edu/Pubs/ETD/Available/etd-051807-164436/unrestricted/EAMPADU.pdf Find differences between high order derivative values - Approximate differential equations by finite differences at evenly spaced data points Based on forward & backward Taylor series expansion of f(x) about x plus or minus multiples of delta h. Forward / backward difference - the sums of the series contains even derivatives and the difference of the series contains odd derivatives – coupled equations that can be solved. Provide an approximation of the derivative within a O(h^2) accuracy There is also central difference & extended central difference which has a O(h^4) accuracy Richardson Extrapolation http://en.wikipedia.org/wiki/Richardson_extrapolation C++: http://mathscoding.blogspot.co.il/2012/02/introduction-richardson-extrapolation.html A sequence acceleration method applied to finite differences Fast convergence, high accuracy O(h^4) Derivatives via Interpolation Cannot apply Finite Difference method to discrete data points at uneven intervals – so need to approximate the derivative of f(x) using the derivative of the interpolant via 3 point Lagrange Interpolation Note: the higher the order of the derivative, the lower the approximation precision Numerical Integration Estimate finite & infinite integrals of functions More accurate procedure than numerical differentiation Use when it is not possible to obtain an integral of a function analytically or when the function is not given, only the data points are Newton Cotes Methods http://en.wikipedia.org/wiki/Newton%E2%80%93Cotes_formulas C++: http://www.siafoo.net/snippet/324 For equally spaced data points Computationally easy – based on local interpolation of n rectangular strip areas that is piecewise fitted to a polynomial to get the sum total area Evaluate the integrand at n+1 evenly spaced points – approximate definite integral by Sum Weights are derived from Lagrange Basis polynomials Leverage Trapezoidal Rule for default 2nd formulas, Simpson 1/3 Rule for substituting 3 point formulas, Simpson 3/8 Rule for 4 point formulas. For 4 point formulas use Bodes Rule. Higher orders obtain more accurate results Trapezoidal Rule uses simple area, Simpsons Rule replaces the integrand f(x) with a quadratic polynomial p(x) that uses the same values as f(x) for its end points, but adds a midpoint Romberg Integration http://en.wikipedia.org/wiki/Romberg's_method C++: http://code.google.com/p/romberg-integration/downloads/detail?name=romberg.cpp&can=2&q= Combines trapezoidal rule with Richardson Extrapolation Evaluates the integrand at equally spaced points The integrand must have continuous derivatives Each R(n,m) extrapolation uses a higher order integrand polynomial replacement rule (zeroth starts with trapezoidal) à a lower triangular matrix set of equation coefficients where the bottom right term has the most accurate approximation. The process continues until the difference between 2 successive diagonal terms becomes sufficiently small. Gaussian Quadrature http://en.wikipedia.org/wiki/Gaussian_quadrature C++: http://www.alglib.net/integration/gaussianquadratures.php Data points are chosen to yield best possible accuracy – requires fewer evaluations Ability to handle singularities, functions that are difficult to evaluate The integrand can include a weighting function determined by a set of orthogonal polynomials. Points & weights are selected so that the integrand yields the exact integral if f(x) is a polynomial of degree <= 2n+1 Techniques (basically different weighting functions): · Gauss-Legendre Integration w(x)=1 · Gauss-Laguerre Integration w(x)=e^-x · Gauss-Hermite Integration w(x)=e^-x^2 · Gauss-Chebyshev Integration w(x)= 1 / Sqrt(1-x^2) Solving ODEs Use when high order differential equations cannot be solved analytically Evaluated under boundary conditions RK for systems – a high order differential equation can always be transformed into a coupled first order system of equations Euler method http://en.wikipedia.org/wiki/Euler_method C++: http://rosettacode.org/wiki/Euler_method First order Runge–Kutta method. Simple recursive method – given an initial value, calculate derivative deltas. Unstable & not very accurate (O(h) error) – not used in practice A first-order method - the local error (truncation error per step) is proportional to the square of the step size, and the global error (error at a given time) is proportional to the step size In evolving solution between data points xn & xn+1, only evaluates derivatives at beginning of interval xn à asymmetric at boundaries Higher order Runge Kutta http://en.wikipedia.org/wiki/Runge%E2%80%93Kutta_methods C++: http://www.dreamincode.net/code/snippet1441.htm 2nd & 4th order RK - Introduces parameterized midpoints for more symmetric solutions à accuracy at higher computational cost Adaptive RK – RK-Fehlberg – estimate the truncation at each integration step & automatically adjust the step size to keep error within prescribed limits. At each step 2 approximations are compared – if in disagreement to a specific accuracy, the step size is reduced Boundary Value Problems Where solution of differential equations are located at 2 different values of the independent variable x à more difficult, because cannot just start at point of initial value – there may not be enough starting conditions available at the end points to produce a unique solution An n-order equation will require n boundary conditions – need to determine the missing n-1 conditions which cause the given conditions at the other boundary to be satisfied Shooting Method http://en.wikipedia.org/wiki/Shooting_method C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-shooting-method-for-solving.html Iteratively guess the missing values for one end & integrate, then inspect the discrepancy with the boundary values of the other end to adjust the estimate Given the starting boundary values u1 & u2 which contain the root u, solve u given the false position method (solving the differential equation as an initial value problem via 4th order RK), then use u to solve the differential equations. Finite Difference Method For linear & non-linear systems Higher order derivatives require more computational steps – some combinations for boundary conditions may not work though Improve the accuracy by increasing the number of mesh points Solving EigenValue Problems An eigenvalue can substitute a matrix when doing matrix multiplication à convert matrix multiplication into a polynomial EigenValue For a given set of equations in matrix form, determine what are the solution eigenvalue & eigenvectors Similar Matrices - have same eigenvalues. Use orthogonal similarity transforms to reduce a matrix to diagonal form from which eigenvalue(s) & eigenvectors can be computed iteratively Jacobi method http://en.wikipedia.org/wiki/Jacobi_method C++: http://people.sc.fsu.edu/~jburkardt/classes/acs2_2008/openmp/jacobi/jacobi.html Robust but Computationally intense – use for small matrices < 10x10 Power Iteration http://en.wikipedia.org/wiki/Power_iteration For any given real symmetric matrix, generate the largest single eigenvalue & its eigenvectors Simplest method – does not compute matrix decomposition à suitable for large, sparse matrices Inverse Iteration Variation of power iteration method – generates the smallest eigenvalue from the inverse matrix Rayleigh Method http://en.wikipedia.org/wiki/Rayleigh's_method_of_dimensional_analysis Variation of power iteration method Rayleigh Quotient Method Variation of inverse iteration method Matrix Tri-diagonalization Method Use householder algorithm to reduce an NxN symmetric matrix to a tridiagonal real symmetric matrix vua N-2 orthogonal transforms     Whats Next Outside of Numerical Methods there are lots of different types of algorithms that I’ve learned over the decades: Data Mining – (I covered this briefly in a previous post: http://geekswithblogs.net/JoshReuben/archive/2007/12/31/ssas-dm-algorithms.aspx ) Search & Sort Routing Problem Solving Logical Theorem Proving Planning Probabilistic Reasoning Machine Learning Solvers (eg MIP) Bioinformatics (Sequence Alignment, Protein Folding) Quant Finance (I read Wilmott’s books – interesting) Sooner or later, I’ll cover the above topics as well.

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  • CHM to EPUB Converter

    - by griegs
    I recently bought an iriver ebook reader but it doesn't support chm files. I have bought a bunch of O'Reilly books and with them have the soft copy as well. Some books convert quite well using calibre. However, there is one book I have that just won't convert. So I used HH to decompile it and now I have a bunch of html files. These html files contain references to images in folders. How can I now join them all into a single document which Calibre can read and properly convert into an epub or am I going about this the wrong way? I've read this question but it removes the images and the images are quite important to the content.

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