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  • Rails - Associations - Automatically setting an association_id for a model which has 2 belongs_to

    - by adam
    I have 3 models class User < ... belongs_to :language has_many :posts end class Post < ... belongs_to :user belongs_to :language end class Language < ... has_many :users has_many :posts end Im going to be creating lots of posts via users and at the same time I have to also specify the language the post was written in, which is always the language associatd with the user i.e. @user.posts.create(:text => "blah", :language_id => @user.language_id) That's fine but the way I set the language doesn't sit well with me. The language will always be that of the users so is there a 'best-practice' way of doing this? I know a little about callbacks and association extensions but not sure of any pitfalls.

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  • Best way to model Installation logic/flow

    - by Ian
    Hi All, We are currently working on designing the installer for our product. We are currently on the design phase and I'm wondering what is the best diagram (UML or not) to use when modeling installation logic or flow? Currently, we are using the good'ol flowchart. Thanks!

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  • Perceptron Classification and Model Training

    - by jake pinedo
    I'm having an issue with understanding how the Perceptron algorithm works and implementing it. cLabel = 0 #class label: corresponds directly with featureVectors and tweets for m in range(miters): for point in featureVectors: margin = answers[cLabel] * self.dot_product(point, w) if margin <= 0: modifier = float(lrate) * float(answers[cLabel]) modifiedPoint = point for x in modifiedPoint: if x != 0: x *= modifier newWeight = [modifiedPoint[i] + w[i] for i in range(len(w))] w = newWeight self._learnedWeight = w This is what I've implemented so far, where I have a list of class labels in answers and a learning rate (lrate) and a list of feature vectors. I run it for the numbers of iterations in miter and then get the final weight at the end. However, I'm not sure what to do with this weight. I've trained the perceptron and now I have to classify a set of tweets, but I don't know how to do that. EDIT: Specifically, what I do in my classify method is I go through and create a feature vector for the data I'm given, which isn't a problem at all, and then I take the self._learnedWeight that I get from the earlier training code and compute the dot-product of the vector and the weight. My weight and feature vectors include a bias in the 0th term of the list so I'm including that. I then check to see if the dotproduct is less than or equal to 0: if so, then I classify it as -1. Otherwise, it's 1. However, this doesn't seem to be working correctly.

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  • Correct way to model recursive relationship in Django

    - by Yuval A
    My application has two node types: a parent node which can hold recursive child nodes. Think of it like the post-comment system in SO, but comments can be recursive: parent_1 child_11 child_12 child_121 child_3 parent_2 child_21 child_211 child_2111 Important to note that the parent nodes have different attributes and behavior than the child nodes. What is the correct (and presumably most efficient) way of modeling this relationship in Django?

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  • flash video covering JQueryUI model dialog

    - by user200295
    I have a site with a flash SWF on the home page. I have a login dialog that is displayed using the jquery ui modal. The modal dialog is being covered by the SWF movie when it opens. I tried setting the z-index etc but nothing seems to stop the SWF from covering the log in. Is there any way to force the SWF movie to the background? The SWF uses src="support/AC_RunActiveContent.js" if that helps isolate the version.

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  • Modifying a model and texture mid-game code

    - by MicroPirate
    Just have a question for anyone out there who knows some sort of game engine pretty well. What I am trying to implement is some sort of script or code that will allow me to make a custom game character and textures mid-game. A few examples would be along the lines of changing facial expressions and body part positions in the game SecondLife. I don't really need a particular language, feel free to use your favorite, I'm just really looking for an example on how to go about this. Also I was wondering if there is anyway to combine textures for optimization; for example if i wanted to add a tattoo to a character midgame, is there any code that could combine his body texture and the tattoo texture into one texture to use (this way I can simply just render one texture per body.) Any tips would be appreciated, sorry if the question is a wee bit to vauge.

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  • Generate XSD from my model

    - by Coppermill
    I am writing a WCF REST service, and I am needing to generate my XSD's which provide the information for my models. What is the easiest way of doing this? It would be nice to have it generate the validation within the XSD too, if possible?

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  • Mocking using 'traditional' Record/Replay vs Moq model

    - by fung
    I'm new to mocks and am deciding on a mock framework. The Moq home quotes Currently, it's the only mocking library that goes against the generalized and somewhat unintuitive (especially for novices) Record/Reply approach from all other frameworks. Can anyone explain simply what the Record/Replay approach is and how Moq differs? What are the pros and cons of each especially from the point of deciding a framework? Thanks.

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  • Automatically generate buddy classes from model in C#

    - by JohnnyO
    I use Linq to Sql (although this is equally applicable in Entity Framework) for my models, and I'm finding myself creating buddy classes for my models all the time. I find this time consuming and repetitive. Is there an easy way to automatically generate these buddy classes based on the models? Perhaps a visual studio macro? An example of a buddy class that I'd like to create: [MetadataType(typeof(PersonMetadata))] public partial class Person { } public class PersonMetadata { public object Id { get; set; } public object FirstName { get; set; } } Thanks in advance.

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  • ER Data Model - confused by diagram.

    - by Khou
    Hi im a little confused by this diagram http://www.b-eye-network.com/images/content/i030ht0104.gif (Last diagram in the article) 1 - In the "ACCOUNTING ENTRY" table it shows "DebitEntry" and "CreditEntry" i) is this two column or ii) is this two rows of data? or iii) is it two separate tables on its own, Acounting_entry_credit and Accounting_entry_debit? Same question with the "ACCOUNT" table, it shows asset account, livabilities account, equaity account? are they 3 columns or are they 3 rows? Source: http://www.tdan.com/view-articles/5227/

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  • How to model a social news feed on Google App Engine

    - by PEZ
    We want to implement a "News feed" where a user can see messages broadcasted by her friends, sorted with newest message first. But the feed should reflect changes in her friends list. (If she adds new friends, messages from those should be included in the feed, and if she removes friends their messages should not be included.) If we use the pubsub-test example and attach a recipient list to each message this means a lot of manipulation of the message recipients lists when users connect and disconnect friends. We first modeled publish-subscribe "fan out" using conventional RDBMS thinking. It seemed to work at first, but then, since the IN operator works the way it does, we quickly realized we couldn't continue on that path. We found Brett Slatkin's presentation from last years Google I/O and we have now watched it a few times but it isn't clear to us how to do it with "dynamic" recipient lists. What we need are some hints on how to "think" when modeling this.

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  • When to use which mysql partitioning model

    - by Industrial
    Ok guys, just starting out with partitioning some tables in mySQL. There's a couple of different ways describing this, but what I cant find is a more practical approach. - Which type of data does each way of partitioning have the best effect on? Or doesn't it really matter?

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  • Updating Model with entity collection

    - by jean27
    There are a group of entities named Book and Magazine which inherits from the abstract class PublishedItem. PublishedItem have these properties: ID, Name, Publisher, List of Authors, List of Genres. The Book entity has the ISBN property and the Magazine entity has the ISSN property. I just want to ask how I can update the book's or magazine's list of genres or list of authors?

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  • Entity Framework - in model first, how do I get my EF classes to be based on the existing domain cla

    - by Greg
    Hi, If I already have domain classes, and I want to be able persist them using EF via a model first approach how do I do this? For example do I go to the EF designer (in VS2010) and create the model and generate the classes, then go to these EF classes and somehow manually modify them? But then would there be an issue if I needed to change the model and re-create database TSQL from the model for updates? What's the easiest approach?

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  • Find model records by ID in the order the array of IDs were given

    - by defaye
    I have a query to get the IDs of people in a particular order, say: ids = [1, 3, 5, 9, 6, 2] I then want to fetch those people by Person.find(ids) But they are always fetched in numerical order, I know this by performing: people = Person.find(ids).map(&:id) => [1, 2, 3, 5, 6, 9] How can I run this query so that the order is the same as the order of the ids array? I made this task more difficult as I wanted to only perform the query to fetch people once, from the IDs given. So, performing multiple queries is out of the question. I tried something like: ids.each do |i| person = people.where('id = ?', i) But I don't think this works.

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  • Android: DOM-Model to XML

    - by poeschlorn
    Hey Guys, analogue to this one (http://stackoverflow.com/questions/2788345/replacing-xml-in-file-from-document-in-java or http://www.exampledepot.com/egs/javax.xml.transform/WriteDom.html) I try to use it under Android... The problem is, that I can't use the suggested solution under android, because it throws java.lang.verifyError... After reading a little bit, I found out, that the class that was used to store the data to file, is not usable in android... can you suggest another solution, which is similar easy to use?

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  • Ejb Update Model from selectOneMenu

    - by Ignacio
    Can anyone please tell me why the following isn't working? h:selectOneMenu value="#{modelosController.selected.idMarca}" f:selectItems value="#{marcasController.itemsAvailableSelectOne}" / /h:selectOneMenu h:commandButton action="#{modelosController.createByMarcas}" value="Buscar" / public String createByMarcas() { current = new Modelos(selectedItemIndex, current.getIdMarca()); items =(DataModel)ejbFacade.findByMarcas(); getPagination().getItemsCount(); recreateModel(); return "List"; } public List<Modelos> findByMarcas(){ CriteriaQuery cq = (CriteriaQuery) em.createNamedQuery("SELECT m FROM Modelos WHERE m.id_marca :id_marca"); cq.select(cq.from(Modelos.class)); return em.createQuery(cq).getResultList(); } Thank you very much!

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  • Database model for saving random boolean expressions

    - by zarko.susnjar
    I have expressions like this: (cat OR cats OR kitten OR kitty) AND (dog OR dogs) NOT (pigeon OR firefly) Anyone having idea how to make tables to save those? Before I got request for usage of brackets, I limited usage of operators to avoid ambiguous situations. So only ANDs and NOTs or only ORs and saved those in this manner: operators id | name 1 | AND 2 | OR 3 | NOT keywords id | keyword 1 | cat 2 | dog 3 | firefly expressions id | operator | keywordId 1 | 0 | 1 1 | 1 | 2 1 | 3 | 3 which was: cat AND dog NOT firefly But now, I'm really puzzled...

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  • Using attr_accessible in a join model with has_many :through relationship

    - by Paulo Oliveira
    I have a USER that creates a COMPANY and become an EMPLOYEE in the process. The employees table has an :user_id and a :company_id. class User has_many :employees has_many :companies, :through => :employees class Employee belongs_to :user belongs_to :company attr_accessible :active class Company has_many :employees has_many :users, :through => employees Pretty basic. But here's the thing, the resource EMPLOYEE has other attributes than its foreign keys, like the boolean :active. I would like to use attr_accessible, but this causes some problems. The attribute :user_id is set right, but :company_id is nil. @user.companies << Company.new(...) Employee id:1 user_id:1 company_id:nil So my question is: if :user_id is set right, despite it is not an attr_accessible, why :company_id isn't set right just the same? It shouldn't be an attr_accessible. I'm using Rails 3.0.8, and have also tested with 3.0.7.

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  • Why can't I save my model with a generic relation twice in Django?

    - by e-satis
    I got a model TrackedItem with a generic relation linking to any model it is supposed to track. If I do that: t = TrackedItem(content_object=MyModel) t.save() t.save() I get : IntegrityError: (1062, "Duplicate entry '1' for key 'PRIMARY'") Indeed, the first save has created an entry with "1" as a PK. But the second save should not insert, it should update. How am I suppose to update a model I can't save twice? With an ordinary model I can save as much as I want.

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  • Difference between KeywordQuery, FullTextQuerySearch type for Object Model and Web service Query

    - by Raghu
    Initially I believed these 3 to be doing more or less the same thing with just the notation being different. Until recently, when i noticed that their does exists a big difference between the results of the KeyWordQuery/FullTextQuerySearch and Web service Query. I used both KeywordQuery and FullText method to search of the the value of a customColumn XYZ with value (ASDSADA-21312ASD-ASDASD):- When I run this query as:- FullTextSqlQuery:- FullTextSqlQuery myQuery = new FullTextSqlQuery(site); { // Construct query text String queryText = "Select title, path, author, isdocument from scope() where freetext('ASDSADA-21312ASD-ASDASD') "; myQuery.QueryText = queryText; myQuery.ResultTypes = ResultType.RelevantResults; }; // execute the query and load the results into a datatable ResultTableCollection queryResults = myQuery.Execute(); ResultTable resultTable = queryResults[ResultType.RelevantResults]; // Load table with results DataTable queryDataTable = new DataTable(); queryDataTable.Load(resultTable, LoadOption.OverwriteChanges); I get the following result representing the document. * Title: TestPDF * path: http://SharepointServer/Shared Documents/Forms/DispForm.aspx?ID=94 * author: null * isDocument: false Do note the Path and isDocument fields of the above result. Web Service Method Then I tried a Web Service Query method. I used Sharepoint Search Service Tool available at http://sharepointsearchserv.codeplex.com/ and ran the same query i.e. Select title, path, author, isdocument from scope() where freetext('ASDSADA-21312ASD-ASDASD'). This time I got the following results:- * Title: TestPDF * path: http://SharepointServer/Shared Documents/TestPDF.pdf * author: null * isDocument: true Again note the path. While the search results from 2nd method are useful as they provide me the file path exactly, I can't seem to understand why is the method 1 not giving me the same results? Why is there a discrepancy between the two results?

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  • Java paint speed relative to color model

    - by Jon
    I have a BufferedImage with an IndexColorModel. I need to paint that image onto the screen, but I've noticed that this is slow when using an IndexColorModel. However, if I run the BufferedImage through an identity affine transform it creates an image with a DirectColorModel and the painting is significantly faster. Here's the code I'm using AffineTransformOp identityOp = new AffineTransformOp(new AffineTransform(), AffineTransformOp.TYPE_BILINEAR); displayImage = identityOp.filter(displayImage, null); I have three questions 1. Why is painting the slower on an IndexColorModel? 2. Is there any way to speed up the painting of an IndexColorModel? 3. If the answer to 2. is no, is this the most efficient way to convert from an IndexColorModel to a DirectColorModel? I've noticed that this conversion is dependent on the size of the image, and I'd like to remove that dependency. Thanks for the help

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  • Back Orders for ERP: data model references ?

    - by Patrick Honorez
    I have built an ERP using Sql Server as a back-end. These are the different types of Client documents (there are also Supplier Docs): Order -- impact: BO Delivery Note (also used for returns, with negative quantity) --impact: BO, Stock Invoice --impact: accounting only Credit Note --impact: accounting, BO I use a complex system of self joins (at detail level) to find out the quantities in each OrderDetail that still have a backorder (BO). It'd like to simplify this using a [group] field that could be used through all detail line related to an original order. There are many difficult things to trace: a Return of a product may be due to a defect and thus increase the BO, or it can be just a return, joined with a Credit Note, and then has no impact on BO. My question is: do you know of any real good reference (book, web) for this matter ?

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