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• OCR: How to improve accuracy - existing libraries for removing non-text 'furniture', shapes, etc to

  - by Rob

  I want to remove rectangles etc that enclose text in a screenshot image, so that I can perform optical character recognition to get accurate text from the screenshot. Background: I doing this to extract data from a legacy application for use with other applications. This is the only way to get at this data as associated files are in a closed, proprietary, binary format. I will be using AutoItScript to drive the application to show data in its UI, then I will screenshot this and feed this to tesseract. I've already had some success in automating the UI, and have been able to use tesseract to get plain ascii text out of the bitmap. There are several AutoItScripr forum articles discussing its use with tesseract/OCR but not specifically for my question. http://www.autoitscript.com/forum/index.php?s=6c32c3ece12756e635a619cdf175eff9&showforum=2 What I need to do There are thin, 1-pixel wide rectangles that closely enclose some text, when fed to tesseract, it sees them as I for example for a verticle line of the rectangle. Any thoughts on how to remove the rectangles, or best practices? I'm asking if there is a generic command line based toolset to overwrite rectangles, for example, in .png files. I could then pass the .png through this, then pass it to tesseract. Details on the tesseract release/setup I've used are as follows: Go here: http://code.google.com/p/tesseract-ocr/downloads/list - For the basic english generic character set to get Tesseract up and running and recognising your bitmapped text into ascii text, use tesseract-2.00.eng.tar.gz (current version at time of writing is: "English language data for Tesseract (2.00 and up) Jul 2007 989 KB 84845") Related questions I have already looked at on Stack Overflow http://stackoverflow.com/questions/1335581/how-to-give-best-chance-of-success-to-an-ocr-software http://stackoverflow.com/questions/2296568/analysis-and-transformation-of-the-image-on-the-basis-of-this-analysis-for-better http://stackoverflow.com/questions/2268028/reading-characters-off-of-the-screen In these, my question is not completely answered or a commercial solution is being sold. I do not want to consider a commercial solution at this stage.

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• Quantis Quantum Random Number Generator (QRNG) - any reviews?

  - by Tim Post

  I am thinking about getting one of these (PCI) to set up an internal entropy pool similar to this service who incidentally brought us fun captcha challenges. Prior to lightening my wallet, I'm hoping to gather feedback from people who may be using this device. As there is no possible 'correct' answer, I am making this CW and tagging it as subjective. I'm undertaking a project to help write Monte Carlo simulations for a non profit that distributes mosquito nets in Malaria stricken areas. The idea is to model areas to determine the best place to distribute mosquito nets. During development, I expect to consume gigs if not more of the RNG output. We really need our own source. Is this device reliable? Does it have to be re-started often? Is its bandwidth really as advertised? It passes all tests, as far as randomness goes (i.e. NIST/DIEHARD). What I don't want is something in deadlock due to some ioctl in disk sleep that does nothing but radiate heat. This is not a spamvertisement, I'm helping out of pocket and I really, really want to know if such a large purchase will bear fruit. I can't afford to build a HRNG based on radioactive decay, this looks like the next best thing. Any comments are appreciated. I will earn zero rep for this, please do not vote to close. This is no different than questions regarding the utilization of some branded GPU for some odd purpose. Answers pointing to other solutions will be gladly accepted, I'm not married to this idea.

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• ASP.NET MVC Session Expiration

  - by Andrew Flanagan

  We have an internal ASP.NET MVC application that requires a logon. Log on works great and does what's expected. We have a session expiration of 15 minutes. After sitting on a single page for that period of time, the user has lost the session. If they attempt to refresh the current page or browse to another, they will get a log on page. We keep their request stored so once they've logged in they can continue on to the page that they've requested. This works great. However, my issue is that on some pages there are AJAX calls. For example, they may fill out part of a form, wander off and let their session expire. When they come back, the screen is still displayed. If they simply fill in a box (which will make an AJAX call) the AJAX call will return the Logon page (inside of whatever div the AJAX should have simply returned the actual results). This looks horrible. I think that the solution is to make the page itself expire (so that when a session is terminated, they automatically are returned to the logon screen without any action by them). However, I'm wondering if there are opinions/ideas on how best to implement this specifically in regards to best practices in ASP.NET MVC.

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• WPF creating custom control - creating control like SpinBox extending TextBox

  - by veedoo

  Hi, What is the best way to extend a control? Lets choose for example SpinBox - we want to extend TextBox to SpinBox - just to add two buttons on the right side, which each one on click checks if Text property is a valid number and if it is increases or decreases the value by 1. Suposse that we have a lot of code using TextBox (Text, IsReadOnly properties and bindings etc.) so we want to replace TextBox by SpinBox without touching rest of the code. 1) we can inherit TextBox - so we have exactly the same interface, but how to add the buttons ?? 2) we can inherit from some layout control - eg. DockPanel - we can add buttons, but we lose TextBox interface. 3) after quick read about ControlTemplates I'm not sure, but I believe that we can add buttons and their logic using ControlTemplates 4) like about templates I'm not sure, but I hope we can inherit decorator class to create decorator with the buttons - we lose interface, but can add TextBox as a child I think that the best solutions is to combine 3) and 4) - create a decorator class and use it in a control template for TextBox. I would be grateful for your ideas and simple code how to implement 3 and 4, especially with code (c#), not xaml. Regards

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• Cannot use READPAST in snapshot isolation mode

  - by Marcus

  I have a process which is called from multiple threads which does the following: Start transaction Select unit of work from work table with by finding the next row where IsProcessed=0 with hints (UPDLOCK, HOLDLOCK, READPAST) Process the unit of work (C# and SQL stored procedures) Commit the transaction The idea of this is that a thread dips into the pool for the "next" piece of work, and processes it, and the locks are there to ensure that a single piece of work is not processed twice. (the order doesn't matter). All this has been working fine for months. Until today that is, when I happened to realise that despite enabling snapshot isolation and making it the default at the database level, the actual transaction creation code was manually setting an isolation level of "ReadCommitted". I duly changed that to "Snapshot", and of course immediately received the "You can only specify the READPAST lock in the READ COMMITTED or REPEATABLE READ" error message. Oops! The main reason for locking the row was to "mark the row" in such a way that the "mark" would be removed when the transaction that applied the mark was committed and the lock seemed to be the best way to do this, since this table isn't read otherwise except by these threads. If I were to use the IsProcessed flag as the lock, then presumably I would need to do the update first, and then select the row I just updated, but I would need to employ the NOLOCK flag to know whether any other thread had set the flag on a row. All sounds a bit messy. The easiest option would be to abandon the snapshot isolation mode altogether, but the design of step #3 requires it. Any bright ideas on the best way to resolve this problem? Thanks Marcus

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• [OffTopic] PhD is it worth it?

  - by Zenzen

  So I'll be graduating next year (hopefully) and lately I started thinking about getting a PhD in computer science (to be more precise I was thinking about something related to "distributed systems", don't have any specific topics yet in mind), but is it really worth it? A PhD course here lasts 4 years and is free IF you're doing the "normal one" (which means you have class from monday to friday) OR you have to pay if you want to study on the weekends. So I've been thinking about getting a normal full time job (as a JEE programmer) and doing my PhD during the weekends OR doing the normal PhD course (mon-fri) and getting a part time job as a software dev (the main reason I want a job is simple - I need to eat). That would give me practical working experience and theoretical knowledge+a PhD, but it would also mean working 7days a week from 9 to 5 for 4 years straight (sounds like an overkill). Is it, job wise, really worth getting a PhD? As an employer do you prefer people with PhDs or MScs? This might be kinda important - I'm not from the US or western europe, how are PhDs from other countries (I am graduating one of the best, if not the best, school in my country but it's still a central european country...) seen? Are they useless? I won't hide it - after graduation I am thinking about moving abroad.

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• How to print data form C#

  - by Hybryd

  I've searched Stackoverflow and google and found many ways how I can print stuff in C#. The best way for me would be to populate blank white windows form with some label, textbox and picturebox elements and print it as a windows form. This way is very poor because it prints in 72 DPI, and is not flexible for multiple pages print. Next way that I found that would be good is using iTextSharp, but there is a problem that iTextSharp only generates PDF-s, and you have to open it in PDF viewer and print from there. I love this way of thinking where I create a paragraph, and then fill it with text and graphic, so I found this thread http://www.devarticles.com/c/a/C-Sharp/Printing-Using-C-sharp/ where it discusses how to create your own printing engine in C#, something like iTextSharp, but very lightweight... Now that I've said that, I want to know is there any ready to use printing engine that would be like iTextSharp, made for printing, not for PDF generation? What is the best way to print something, without using reporting services like CrystalReports. I think Crystal Reports wouldn't work for my case cause I don't want to print generic reports, but some text and graphics that I need to dynamicaly generate every time I need to print.

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• Problem trying to install PyCurl on Mac Snow Leopard

  - by Ldn

  Hi, My app needs to use PyCurl, so i tried to install it on my Mac but i found a lot of problems and error :( Requirement: First of all i've to say that the version of Python working on my Mac is 32 bit based, because i need to use WxPython, that needs 32 bit Python. For doing this i used: defaults write com.apple.versioner.python Prefer-32-Bit -bool yes To install PyCurl i used: sudo env ARCHFLAGS="-arch x86_64" easy_install setuptools pycurl And the terminal returned: Best match: setuptools 0.6c11 Processing setuptools-0.6c11-py2.6.egg setuptools 0.6c11 is already the active version in easy-install.pth Installing easy_install script to /usr/local/bin Installing easy_install-2.6 script to /usr/local/bin Using /Library/Python/2.6/site-packages/setuptools-0.6c11-py2.6.egg Processing dependencies for setuptools Finished processing dependencies for setuptools Searching for pycurl Best match: pycurl 7.16.2.1 Processing pycurl-7.16.2.1-py2.6-macosx-10.6-universal.egg pycurl 7.16.2.1 is already the active version in easy-install.pth Using /Library/Python/2.6/site-packages/pycurl-7.16.2.1-py2.6-macosx-10.6-universal.egg Processing dependencies for pycurl Finished processing dependencies for pycurl so i thought that pycurl was correctly installed and working. But... But when i started my app, python return me an error: python /Users/lorenzodenobili/Desktop/Python/AGGIORNATORE_PY/Dropbox/wxPython/test.py Traceback (most recent call last): File "/Users/lorenzodenobili/Desktop/Python/AGGIORNATORE_PY/Dropbox/wxPython/test.py", line 20, in <module> import pycurl File "build/bdist.macosx-10.6-universal/egg/pycurl.py", line 7, in <module> File "build/bdist.macosx-10.6-universal/egg/pycurl.py", line 6, in __bootstrap__ ImportError: dlopen(/Users/lorenzodenobili/.python-eggs/pycurl-7.16.2.1-py2.6-macosx-10.6-universal.egg-tmp/pycurl.so, 2): no suitable image found. Did find: /Users/lorenzodenobili/.python-eggs/pycurl-7.16.2.1-py2.6-macosx-10.6-universal.egg-tmp/pycurl.so: mach-o, but wrong architecture Yep, there is something quite big that goes wrong. I really don't have any idea on how to solve this error, so i really need your help! thank you so much!!

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• How to arrange models, views, controllers in a new Kohana 3 project

  - by Pekka

  I'm looking at how to set up a mid-sized web application with Kohana 3. I have implemented MVC patterns in the past but never worked against a "formalized" MVC framework so I'm still getting my head around the terminology - toying around with basic examples, building views and templates, and so on. I'm progressing fairly well but I want to set up a real-world web project (one of my own that I've been planning for quite some time now) as a learning object. Example-based documentation is a bit sparse for Kohana 3 right now - they say so themselves on the site. While I'm not worried about learning the framework soon enough, I'm a bit at a loss on how to arrange a healthy code base from the start - i.e. how to split up controllers, how to name them, and how to separate the functionality into the appropriate models. My application could, in its core, be described as a business directory with a main businesses table. Businesses can be listed by category and by street name. Each business has a detail page. Business owners can log in and edit their business's entry. Businesses can post offers into an offers table. I know this is pretty vague, I'll be more than happy to go into more detail on request. Supposing I have all the basic functionality worked out and in place already - list all businesses, edit business, list businesses by street name, create offer, and so on, and I'm just looking for how to fit the functionality into a Kohana application structure that can be easily extended: Do you know real-life, publicly accessible examples of applications built on Kohana 3 where I could take a peek how they do it? Are there conventions or best practices on how to structure an extendable login area for end users in a Kohana project that is not only able to handle a business directory page, but further products on separate pages as well? Do you know application structuring HOWTOs or best practices for Kohana 3 not mentioned in the user guide and the inofficial Wiki? Have you built something similar and could give me some recommendations?

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• Help needed implementing a web based file management system with a file hierarchy system, help neede

  - by molleman

  Hello i am trying to create a web application that will allow users to upload files online, i am using gwt while using hibernate for database communication, i am able to upload file to a server , and store them on the server. but what i want is to associate the files with a user. i want the user to be able to create folders and store a file in sub folders. my logic was to use the composite pattern to store folders and fileLocations with a user but i am am finding it difficult to implement this so i can show the files and folders within a gwt tree. what would be the best way to implement a hierarchy of folders and information of the location of a file so it could be displayed in a gwt tree? what i did have was a User would hold a reference to a root folder and then each sub folder could hold folders or fileLocations. i used the composite pattern to implement the file hierarchy, but when i want to display a the contents of a folder i need a for loop for each list. so i could a folder within a folder within a folder that would need 3 for loops to show the contents of my folders. What is the best way to implement this file management system. so what do you guys think?

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• Db4o Mvc Application Architecture

  - by Mac

  I am currently testing out Db4o for an asp.net MVC 2 application idea but there are a few things I'm not quite sure on the best way to proceed. I want my application to use guessable routes rather than Id's for referencing my entities but I also think I need Id's of some sort for update scenarios. so for example I want /country/usa instead of /country/1 I may want to change the key name though (not perhaps on a country but on other entities) so am thinking I need an Id to use as the reference to retrieve the object prior to updating it's fields. From other comments it seems like the UUID is a bit long to be using and would prefer to use my own id's anyway for clean separation of concerns. Looking at both the KandaAlpha project I wasn't too keen on some aspects of the design and prefer something more along the lines of S#arp architecture where they use things like the [domainsignature] and EntityWithTypedId, IEntityDuplicateChecker, IHasAssignedId, BaseObject and IValidatable in their entities to control insert/update behaviour which seems cleaner and more extensible, covers validation and is encapsulated well within the core and base repository classes. So would a port of S#arp architecture to Db4o make sense of am I still thinking rmdbs in an oodb world? Also is there a best practice for managing indexes (including Unique ones as above) in Db4o? Should they be model metadata based and loaded using DI in a bootstrapper for example or should they be more loaded more like Automapper.CreateMap? Its a bit of a rambling question I know but any thoughts, ideas or suggested reading material is greatly appreciated. Thanks Mac

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• Working with a large data object between ruby processes

  - by Gdeglin

  I have a Ruby hash that reaches approximately 10 megabytes if written to a file using Marshal.dump. After gzip compression it is approximately 500 kilobytes. Iterating through and altering this hash is very fast in ruby (fractions of a millisecond). Even copying it is extremely fast. The problem is that I need to share the data in this hash between Ruby on Rails processes. In order to do this using the Rails cache (file_store or memcached) I need to Marshal.dump the file first, however this incurs a 1000 millisecond delay when serializing the file and a 400 millisecond delay when serializing it. Ideally I would want to be able to save and load this hash from each process in under 100 milliseconds. One idea is to spawn a new Ruby process to hold this hash that provides an API to the other processes to modify or process the data within it, but I want to avoid doing this unless I'm certain that there are no other ways to share this object quickly. Is there a way I can more directly share this hash between processes without needing to serialize or deserialize it? Here is the code I'm using to generate a hash similar to the one I'm working with: @a = [] 0.upto(500) do |r| @a[r] = [] 0.upto(10_000) do |c| if rand(10) == 0 @a[r][c] = 1 # 10% chance of being 1 else @a[r][c] = 0 end end end @c = Marshal.dump(@a) # 1000 milliseconds Marshal.load(@c) # 400 milliseconds Update: Since my original question did not receive many responses, I'm assuming there's no solution as easy as I would have hoped. Presently I'm considering two options: Create a Sinatra application to store this hash with an API to modify/access it. Create a C application to do the same as #1, but a lot faster. The scope of my problem has increased such that the hash may be larger than my original example. So #2 may be necessary. But I have no idea where to start in terms of writing a C application that exposes an appropriate API. A good walkthrough through how best to implement #1 or #2 may receive best answer credit.

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• Load Balance WCF and Share a Remote MSMQ for High Throughput

  - by BarDev

  After a ton of reading in books and on the web, I have noticed hints of information that WCF and MSMQ can be used in achieving high throughput. The information I have seen mentions using multiple WCF services in a farm that reads from a single MSMQ queue. The problem is that I have found paragraphs here and there that mentions that high throughput can be done, but I cannot seem to find a document of how to implement it. The following is an excerpt from a MSDN article. The following paragraph is from Best Practices for Queued Communication http://msdn.microsoft.com/en-us/library/ms731093.aspx To achieve higher throughput and availability, use a farm of WCF services that read from the queue. This requires that all of these services expose the same contract on the same endpoint. The farm approach works best for applications that have high production rates of messages because it enables a number of services to all read from the same queue. This is what I'm trying to solve. I have an intranet application where a client sends a request to a WCF service. But I want the ability to load balance the WCF services on multiple servers in a farm. I also want these WCF services in the farm to do transactional reads from a remote MSMQ when an item is available in the Queue. If this is possible, an issue I have is that I do not understand the activation process of WCF to retrieve messages from a remote queue. If this is possible, does anyone know of any articles or Webcasts that would explain it in detail? BarDev

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• NHibernate Generators

  - by Dan

  What is the best tool for generating Entity Class and/or hbm files and/or sql script for NHibernate. This list below is from http://www.hibernate.org/365.html, which is the best any why? Moregen Free, Open Source (GPL) O/R Generator that can merge into existing Visual Studio Projects. Also merges changes to generated classes. NConstruct Lite Free tool for generating NHibernate O/R mapping source code. Different databases support (Microsoft SQL Server, Oracle, Access). GENNIT NHibernate Code Generator Free/Commercial Web 2.0 code generation of NHibernate code using WYSIWYG online UML designer. GenWise Studio with NHibernate Template Commercial product; Imports your existing database and generates all XML and Classes, including factories. It can also generate a asp.net web-application for your NHibernate BO-Layer automatically. HQL Analyzer and hbm.xml GUI Editor ObjectMapper by Mats Helander is a mapping GUI with NHibernate support MyGeneration is a template-based code generator GUI. Its template library includes templates for generating mapping files and classes from a database. AndroMDA is an open-source code generation framework that uses Model Driven Architecture (MDA) to transform UML models into deployable components. It supports generation of data access layers that use NHibernate as their persistence framework. CodeSmith Template for NH NHibernate Helper Kit is a VS2005 add-in to generate classes and mapping files. NConstruct - Intelligent Software Factory Commercial product; Full .NET C# source code generation for all tiers of the information system trough simple wizard procedure. O/R mapping based on NHibernate. For both WinForms and ASP.NET 2.0.

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• WMD markdown editor - HTML to Markdown conversion

  - by gg1

  I am using wmd markdown editor on a project and had a question: When I post the form containing the markdown text area, it (as expected) posts html to the server. However, say upon server-side validation something fails and I need to send the user back to edit their entry, is there anyway to refill the textarea with just the markdown and not the html? Since as I have it set up, the server only has access to the post data (which is in the form of html) so I can't seem to think of a way to do this. Any ideas? Preferably a non-javascript based solution. Update: I found an html to markdown converter called markdownify. I guess this might be the best solution for displaying the markdown back to the user...any better alternatives are welcome! Update 2: I found this post on SO and I guess there is an option to send the data to the server as markdown instead of html. Are there any downsides to simply storing the data as markdown in the database? What about displaying it back to the user (outside of an editor)? Maybe it would be best to post both versions (html AND markdown) to the server... SOLVED: I can simply use php markdown to convert the markdown to html serverside.

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• WPF Usercontrol interaction with parent view / viewmodel

  - by obaylis

  Hi I have a mainView window which has its dataContext set to it's own viewModel. On that viewModel is a DateTime property which in turn is bound to a datepicker on my main view using 2 way binding. <toolkit:DatePicker DateSelected="{Binding mainDateTimeProperty, Mode=TwoWay}" /> This is all fine so far. On the change of my datetime property I create a list which is then bound to a datagrid elsewhere on the mainview. This all works fine. My question is to do with a usercontrol I want to add to the main view. I want this usercontrol to be self contained so have created it with it's own viewmodel but it does also need access to mainDateTimeProperty I thought that best way to go would be to create a dependencyProperty on the usercontrol and when I create my control in the main view I bind the dp to the datetime as follows. <uc:MyNewUserControl DateProperty="{Binding mainDateTimeProperty}" /> Trouble is how do I have the usercontrol maintain datacontext with it's viewmodel and yet still have the dependency property bound to a property on the main view model? Hope this is clear. Can post some more code if necessary. Looking for a best practice approach if possible. Thanks very much for any advice.

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• VS Solution and Mercurial repository layout for a c# project with plugins and external libraries.

  - by Joviee

  I'm developing a project in .NET (using C# to be more specific). Using Visual Studio as an IDE. Using Mercurial for version control. I'll be using some third-party libraries: ThirdParty.Foo.dll ThirdParty.Bar.dll ThirdParty.Baz.dll And some in-house libraries: Company.A Company.B Company.C Company.D (References third party libraries) Company.E (References Company.A) The project itself will have the following components: Project.Core Project.DataModel (references in-house/third-party libraries) Project.GUI (references Core, DataModel, and in-house/third-party libraries) Project.PluginOne (references Core, DataModel, and in-house/third-party libraries) Project.PluginTwo (references Core, DataModel, and in-house/third-party libraries) * can be an arbitrary number of plugins * I'm quite new to Mercurial, so I don't really know the best way to structure my repositories for a project like this, with a lot of interconnected components. The in-house libraries are fairly distinct, so I would say that each one of them should have its own repository. However, some of them use functionality provided by others. How should these dependencies be managed? The project plug-ins should be distinct from eachother, so I'd imagine that each would have its own repository. How should the dependencies on the in-house/third-party libraries and the rest of the project (Project.DataModel and Project.Core) be managed, with regards to the solution layout and the repository layout? So basically, for a project like this, what are the best way of structuring: (a) my visual studio solutions (b) my source control repository/repositories

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• dynamically create class in scala, should I use interpreter?

  - by Phil

  Hi, I want to create a class at run-time in Scala. For now, just consider a simple case where I want to make the equivalent of a java bean with some attributes, I only know these attributes at run time. How can I create the scala class? I am willing to create from scala source file if there is a way to compile it and load it at run time, I may want to as I sometimes have some complex function I want to add to the class. How can I do it? I worry that the scala interpreter which I read about is sandboxing the interpreted code that it loads so that it won't be available to the general application hosting the interpreter? If this is the case, then I wouldn't be able to use the dynamically loaded scala class. Anyway, the question is, how can I dynamically create a scala class at run time and use it in my application, best case is to load it from a scala source file at run time, something like interpreterSource("file.scala") and its loaded into my current runtime, second best case is some creation by calling methods ie. createClass(...) to create it at runtime. Thanks, Phil

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• Enum Naming Convention - Plural

  - by o.k.w

  I'm asking this question despite having read similar but not exactly what I want at http://stackoverflow.com/questions/495051/c-naming-convention-for-enum-and-matching-property I found I have a tendency to name enums in plural and then 'use' them as singular, example: public enum EntityTypes { Type1, Type2 } public class SomeClass { /* some codes */ public EntityTypes EntityType {get; set;} } Of course it works and this is my style, but can anyone find potential problem with such convention? I do have an "ugly" naming with the word "Status" though: public enum OrderStatuses { Pending, Fulfilled, Error, Blah, Blah } public class SomeClass { /* some codes */ public OrderStatuses OrderStatus {get; set;} } Additional Info: Maybe my question wasn't clear enough. I often have to think hard when naming the variables of the my defined enum types. I know the best practice, but it doesn't help to ease my job of naming those variables. I can't possibly expose all my enum properties (say "Status") as "MyStatus". My question: Can anyone find potential problem with my convention described above? It is NOT about best practice. Question rephrase: Well, I guess I should ask the question this way: Can someone come out a good generic way of naming the enum type such that when used, the naming of the enum 'instance' will be pretty straightforward?

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• Genetic Algorithms applied to Curve Fitting

  - by devoured elysium

  Let's imagine I have an unknown function that I want to approximate via Genetic Algorithms. For this case, I'll assume it is y = 2x. I'd have a DNA composed of 5 elements, one y for each x, from x = 0 to x = 4, in which, after a lot of trials and computation and I'd arrive near something of the form: best_adn = [ 0, 2, 4, 6, 8 ] Keep in mind I don't know beforehand if it is a linear function, a polynomial or something way more ugly, Also, my goal is not to infer from the best_adn what is the type of function, I just want those points, so I can use them later. This was just an example problem. In my case, instead of having only 5 points in the DNA, I have something like 50 or 100. What is the best approach with GA to find the best set of points? Generating a population of 100, discard the worse 20% Recombine the remaining 80%? How? Cutting them at a random point and then putting together the first part of ADN of the father with the second part of ADN of the mother? Mutation, how should I define in this kind of problem mutation? Is it worth using Elitism? Any other simple idea worth using around? Thanks

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• Django - provide additional information in template

  - by Ninefingers

  Hi all, I am building an app to learn Django and have started with a Contact system that currently stores Contacts and Addresses. C's are a many to many relationship with A's, but rather than use Django's models.ManyToManyField() I've created my own link-table providing additional information about the link, such as what the address type is to the that contact (home, work etc). What I'm trying to do is pass this information out to a view, so in my full view of a contact I can do this: def contact_view_full(request, contact_id): c = get_object_or_404(Contact, id=contact_id) a = [] links = ContactAddressLink.objects.filter(ContactID=c.id) for link in links: b = Address.objects.get(id=link.AddressID_id) a.append(b) return render_to_response('contact_full.html', {'contact_item': c, 'addresses' : a }, context_instance=RequestContext(request)) And so I can do the equivalent of c.Addresses.all() or however the ManyToManyField works. What I'm interested to know is how can I pass out information about the link in the link object with the 'addresses' : a information, so that when my template does this: {% for address in addresses %} <!-- ... --> {% endfor %} and properly associate the correct link object data with the address. So what's the best way to achieve this? I'm thinking a union of two objects might be an idea but I haven't enough experience with Django to know if that's considered the best way of doing it. Suggestions? Thanks in advance. Nf

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• Useful training courses that aren't specific to a single technology

  - by Dave Turvey

  I have possibly the best problem in the world. I have about £1600 left in a training budget and I need to find something to spend it on. I can spend it on anything that could be considered training. Books, courses, conferences, etc. I would like to find a course that would benifit a software developer but is not about learning a specific programming technology. I don't really want to spend it on a technical training course. These topics are usually best learned with a good book and some trial and error. I have also already been on a general business/management training course and a PRINCE2 project management course. I am currently working on a project on my own so am responsible for communicating with the client, requirements gathering, project management, etc., as well as the coding. What training have you found useful outside the usual technical stuff? Has anyone done any business analysis courses? What were they like? Are there any courses on some of the practicalities of working with software, e.g. automated test and deployment strategies, handling technical support? I would prefer a course in the UK but I can travel if necessary.

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• OleDb database to DataSet and back in c#?

  - by Troy

  I'm writing a program that lets a user: Connect to an (arbitrary) View all of the tables in that database in separate DataGridViews Edit them in the program, generate random data, and see the results Choose to commit those changes or revert So I discovered the DataSet class, which looks like it's capable of holding everything that a database would, and I decided that the best thing to do here would be to load everything into one dataset, let the user edit it, and then save the dataset back to the database. The problem is that the only way I can find to load the database tables is this: set = new DataSet(); DataTable schema = connection.GetOleDbSchemaTable( OleDbSchemaGuid.Tables, new string[] { null, null, null, "TABLE" }); foreach (DataRow row in schema.Rows) { string tableName = row.Field<string>("TABLE_NAME"); DataTable dTable = new DataTable(); new OleDbDataAdapter("SELECT * FROM " + tableName, connection).Fill(dTable); dTable.TableName = tableName; set.Tables.Add(dTable); } while it seems like there should be a simpler way given that datasets appear to be designed for exactly this purpose. The real problem though is when I try saving these things. In order to use the OleDbDataAdapter.Update() method, I'm told that I have to provide valid INSERT queries. Doesn't that kind of negate the whole point of having a class to handle this stuff for me? Anyway, I'm hoping somebody can either explain how to load and save a database into a dataset or maybe give me a better idea of how to do what I'm trying to do. I could always parse the commands together myself, but that doesn't seem like the best solution.

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• MySQL Full-Text Search Across Multiple Tables - Quick/Long Solution?

  - by Kerry

  Hello all, I have been doing a bit of research on full-text searches as we realized a series of LIKE statements are terrible. My first find was MySQL full-text searches. I tried to implement this and it worked on one table, failed when I was trying to join multiple tables, and so I consulted stackoverflow's articles (look at the end for a list of the ones I've been to) I didn't see anything that clearly answered my questions. I'm trying to get this done literally in an hour or two (quick solution) but I also want to do a better long term solution. Here is my query: SELECT a.`product_id`, a.`name`, a.`slug`, a.`description`, b.`list_price`, b.`price`, c.`image`, c.`swatch`, e.`name` AS industry FROM `products` AS a LEFT JOIN `website_products` AS b ON (a.`product_id` = b.`product_id`) LEFT JOIN ( SELECT `product_id`, `image`, `swatch` FROM `product_images` WHERE `sequence` = 0) AS c ON (a.`product_id` = c.`product_id`) LEFT JOIN `brands` AS d ON (a.`brand_id` = d.`brand_id`) INNER JOIN `industries` AS e ON (a.`industry_id` = e.`industry_id`) WHERE b.`website_id` = 96 AND b.`status` = 1 AND b.`active` = 1 AND MATCH( a.`name`, a.`sku`, a.`description`, d.`name` ) AGAINST ( 'ashley sofa' ) GROUP BY a.`product_id` ORDER BY b.`sequence` LIMIT 0, 9 The error I get is: Incorrect arguments to MATCH If I remove d.name from the MATCH statement it works. I have a full-text index on that column. I saw one of the articles say to use an OR MATCH for this table, but won't that lose the effectiveness of being able to rank them together or match them properly? Other places said to use UNIONs but I don't know how to do that properly. Any advice would be greatly appreciated. In the idea of a long term solution it seems that either Sphinx or Lucene is best. Now by no means and I a MySQL guru, and I heard that Lucene is a bit more complicated to setup, any recommendations or directions would be great. Articles: http://stackoverflow.com/questions/1117005/mysql-full-text-search-across-multiple-tables http://stackoverflow.com/questions/668371/mysql-fulltext-search-across-1-table http://stackoverflow.com/questions/2378366/mysql-how-to-make-multiple-table-fulltext-search http://stackoverflow.com/questions/737275/pros-cons-of-full-text-search-engine-lucene-sphinx-postgresql-full-text-searc http://stackoverflow.com/questions/1059253/searching-across-multiple-tables-best-practices

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• Suggest a good method with least lookup time complexity

  - by Amrish

  I have a structure which has 3 identifier fields and one value field. I have a list of these objects. To give an analogy, the identifier fields are like the primary keys to the object. These 3 fields uniquely identify an object. Class { int a1; int a2; int a3; int value; }; I would be having a list of say 1000 object of this datatype. I need to check for specific values of these identity key values by passing values of a1, a2 and a3 to a lookup function which would check if any object with those specific values of a1, a2 and a3 is present and returns that value. What is the most effective way to implement this to achieve a best lookup time? One solution I could think of is to have a 3 dimensional matrix of length say 1000 and populate the value in it. This has a lookup time of O(1). But the disadvantages are. 1. I need to know the length of array. 2. For higher identity fields (say 20), then I will need a 20 dimension matrix which would be an overkill on the memory. For my actual implementation, I have 23 identity fields. Can you suggest a good way to store this data which would give me the best look up time?

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