Search Results

Search found 8605 results on 345 pages for 'general dynamics'.

Page 278/345 | < Previous Page | 274 275 276 277 278 279 280 281 282 283 284 285  | Next Page >

  • Returning true or error message in Ruby

    - by seaneshbaugh
    I'm wondering if writing functions like this is considered good or bad form. def test(x) if x == 1 return true else return "Error: x is not equal to one." end end And then to use it we do something like this: result = test(1) if result != true puts result end result = test(2) if result != true puts result end Which just displays the error message for the second call to test. I'm considering doing this because in a rails project I'm working on inside my controller code I make calls to a model's instance methods and if something goes wrong I want the model to return the error message to the controller and the controller takes that error message and puts it in the flash and redirects. Kinda like this def create @item = Item.new(params[:item]) if [email protected]? result = @item.save_image(params[:attachment][:file]) if result != true flash[:notice] = result redirect_to(new_item_url) and return end #and so on... That way I'm not constructing the error messages in the controller, merely passing them along, because I really don't want the controller to be concerned with what the save_image method itself does just whether or not it worked. It makes sense to me, but I'm curious as to whether or not this is considered a good or bad way of writing methods. Keep in mind I'm asking this in the most general sense pertaining mostly to ruby, it just happens that I'm doing this in a rails project, the actual logic of the controller really isn't my concern.

    Read the article

  • Is there a significant mechanical difference between these faux simulations of default parameters?

    - by ccomet
    C#4.0 introduced a very fancy and useful thing by allowing default parameters in methods. But C#3.0 doesn't. So if I want to simulate "default parameters", I have to create two of that method, one with those arguments and one without those arguments. There are two ways I could do this. Version A - Call the other method public string CutBetween(string str, string left, string right, bool inclusive) { return str.CutAfter(left, inclusive).CutBefore(right, inclusive); } public string CutBetween(string str, string left, string right) { return CutBetween(str, left, right, false); } Version B - Copy the method body public string CutBetween(string str, string left, string right, bool inclusive) { return str.CutAfter(left, inclusive).CutBefore(right, inclusive); } public string CutBetween(string str, string left, string right) { return str.CutAfter(left, false).CutBefore(right, false); } Is there any real difference between these? This isn't a question about optimization or resource usage or anything (though part of it is my general goal of remaining consistent), I don't even think there is any significant effect in picking one method or the other, but I find it wiser to ask about these things than perchance faultily assume.

    Read the article

  • python: help defining/installing simple script to setup machine-specific information

    - by Jason S
    (This is related to scons but I think most of the following should be fairly general to python) I would like to define a python file/library that I put in a Well-Known Place somewhere on my computer that I can use to define machine-specific paths, and was looking for help on how to do this well, since I'm a beginner to Python & really only use it for my scons work. scons uses a SConstruct file which can execute python code. What I would like to do is something like this: My SConstruct file would contain this at the beginning: defaultEnv = JJJJJ.getMachineSpecificPaths() or (do both of these syntaxes work?) import JJJJJ defaultEnv = getMachineSpecificPaths() I define a JJJJJ.py file somewhere installed in the python dir which contains the following def getMachineSpecificPaths(): ... does something here, I don't know what ... that reads a file machine-specific-paths.txt (maybe it has the code Ross Rogers mentioned in my other question) located in the same directory as JJJJJ.py containing the following: machine-specific-paths.txt TI_C28_ROOT C:/appl/ti/ccs/?4.1.1/ccsv4/tools/co?mpiler/c2000 JSDB c:/bin/jsdb/jsdb.exe PYTHON_PATH c:/appl/python/2.6.4 The thing is, I don't really know much about the conventions in Python about where you put system-wide libraries and files. This is probably really simple to get right but I don't know how.

    Read the article

  • Should I write more SQL to be more efficient, or less SQL to be less buggy?

    - by RenderIn
    I've been writing a lot of one-off SQL queries to return exactly what a certain page needs and no more. I could reuse existing queries and issue a number of SQL requests linear to the number of records on the page. As an example, I have a query to return People and a query to return Job Details for a person. To return a list of people with their job details I could query once for people and then once for each person to retrieve their job details. I've found that in most cases that solution returns things in a reasonable amount of time, but I don't know how well it will scale in my environment. Instead I've been writing queries to join people + job details, or people + salary history, etc. I'm looking at my models and I see how I could shave off maybe 30% of my code if I were to re-use existing queries. This is a big temptation. Is it a bad thing to go for reuse over efficiency in general or does it all come down to the specific situation? Should I first do it the easy way and then optimize later, or is it best to get the code knocked out while everything is fresh in my mind? Thoughts, experiences?

    Read the article

  • Problem using Lazy<T> from within a generic abstract class

    - by James Black
    I have a generic class that all my DAO classes derive from, which is defined below. I also have a base class for all my entities, but that is not generic. The method GetIdOrSave is going to be a different type than how I defined SabaAbstractDAO, as I am trying to get the primary key to fulfill the foreign key relationships, so this function goes out to either get the primary key or save the entity and then get the primary key. The last code snippet has a solution on how it will work if I get rid of the generic part, so I think this can be solved by using variance, but I can't figure out how to write an interface that will compile. public abstract class SabaAbstractDAO<T> { ... public K GetIdOrSave<K>(K item, Lazy<SabaAbstractDAO<BaseModel>> lazyitemdao) where K : BaseModel { if (item != null && item.Id.IsNull()) { var itemdao = lazyitemdao.Value; item.Id = itemdao.retrieveID(item); if (item.Id.IsNull()) { return itemdao.SaveData(item); } } return item; } } I am getting this error, when I try to compile: Argument 2: cannot convert from 'System.Lazy<ORNL.HRD.LMS.Dao.SabaCourseDAO>' to 'System.Lazy<ORNL.HRD.LMS.Dao.SabaAbstractDAO<ORNL.HRD.LMS.Models.BaseModel>>' I am trying to call it this way: GetIdOrSave(input.OfferingTemplate, new Lazy<SabaCourseDAO>( () => { return new SabaCourseDAO() { Dao = Dao }; }) ); If I change the definition to this, it works. public K GetIdOrSave<K>(K item, Lazy<SabaCourseDAO> lazyitemdao) where K : BaseModel { So, how can I get this to compile using variance (if needed) and generics, so I can have a very general method that will only work with BaseModel and AbstractDAO<BaseModel>? I expect I should only need to make the change in the method and perhaps abstract class definition, the usage should be fine.

    Read the article

  • Different Scala Actor Implementations Overview

    - by Stefan K.
    I'm trying to find the 'right' actor implementation for my thesis. I realized there is a bunch of them and it's a bit confusing to pick one. Personally I'm especially interested in remote actors, but I guess a complete overview would be helpful to many others. This is a pretty general question, so feel free to answer just for the implementation you know about. I know about the following Scala Actor implementations (SAI). Please add the missing ones. Scala 2.7 (difference to) Scala 2.8 Akka (http://www.akkasource.org/) Lift (http://liftweb.net/) Scalaz (http://code.google.com/p/scalaz/) What are the target use-cases for these SAIs (lightweight vs. "heavy" enterprise framework)? do they support remote actors? What shortcomings do remote actors have in the SAIs? How is their performace? How active is there community? How easy are they to get started? How good is the documentation? How easy are they to extend? How stable are they? Which projects are using them? What are their shortcomings? What are their design principles? Are they thread based or event based (receive/ react) or both? Nested receiveS hotswapping the Actor’s message loop

    Read the article

  • Helping Rails Newbies identify version-specific information on web pages

    - by corprew
    I am trying to help some people getting started programming on rails identify which version that advice found on web pages corresponds to, and am seeking advice and/or guides on how to do it so they don't have to rely on me and/or waste time trying outdated advice. Narrative: I am helping some people get up to speed on rails development, and their stock response to running into problems is searching google for advice. They're using 2.3.5 and thinking of moving to 3. The problem they're running into is that there's a lot of advice out there specific to older rails versions (2.2 for example being popular) that isn't identified. I can usually figure out when the pages are old pretty easily, but they can't (yet.) It seems like random web page authors don't identify which version they're using when they're using the current version, and not all pages are dated. This seems to be a general problem that will get worse -- current unadorned advice is usually 2.3.5 and older unadorned advice is 2.2.x at this point, but people are moving / will be moving to version 3 over the next while and newbies will be stuck looking at a bunch of deprecated/incompatible 2.3.x advice without realizing which version it is. Any advice / pointers / telltales?

    Read the article

  • Choosing between .NET Service Bus Queues vs Azure Queue Service

    - by ChrisV
    Just a quick question regarding an Azure application. If I have a number of Web and Worker roles that need to communicate, documentation says to use the Azure Queue Service. However, I've just read that the new .NET Service Bus now also offers queues. These look to be more powerful as they appear to offer a much more detailed API. Whilst the .NSB looks more interesting it has a couple of issues that make me wary of using it in distributed application. (for example, Queue Expiration... if I cannot guarantee that a queue will be renewed on time I may lose it all!). Has anyone had any experience using either of these two technologies and could give any advice on when to choose one over the other. I suspect that whilst the service bus looks more powerful, as my use case is really just enabling Web/Worker roles to communicate between each other, that the Azure Queue Service is what I'm after. But I'm just really looking for confirmation of that before progamming myself in to a corner :-) Thanks in advance. UPDATE Have read up about the two systems over the break. It defo looks like .NET service bus is more specifically designed for integrating systems rather than providing a general purpose reliable messaging system. Azure Queues are distributed and so reliable and scalable in a way that .NSB queues are not and so more suitable for code hosted within Azure itself. Thanks for the responses.

    Read the article

  • Efficient Clojure workflow?

    - by Alex B
    I am developing a pet project with Clojure, but wonder if I can speed up my workflow a bit. My current workflow (with Compojure) is: Start Swank with lein swank. Go to Emacs, connect with M-x slime-connect. Load all existing source files one by one. This also starts a Jetty server and an application. Write some code in REPL. When satisfied with experiments, write a full version of a construct I had in mind. Eval (C-c C-c) it. Switch REPL to namespace where this construct resides and test it. Switch to browser and reload browser tab with the affected page. Tweak the code, eval it, check in the browser. Repeat any of the above. There are a number of annoyances with it: I have to switch between Emacs and the browser (or browsers if I am testing things like templating with multiple browsers) all the time. Is there a common idiom to automate this? I used to have a JavaScript bit that reloads the page continuously, but it's of limited utility, obviously, when I have to interact with the page for more than a few seconds. My JVM instance becomes "dirty" when I experiment and write test functions. Basically namespaces become polluted, especially if I'm refactoring and moving the functions between namespaces. This can lead to symbol collisions and I need to restart Swank. Can I undef a symbol? I load all source files one by one (C-c C-k) upon restarting Swank. I suspect I'm doing it all wrong. Switching between the REPL and the file editor can be a bit irritating, especially when I have a lot of Emacs tabs open, alongside the browser(s). I'm looking for ways to improve the above points and the entire workflow in general, so I'd appreciate if you'd share yours. P. S. I have also used Vimclojure before, so Vimclojure-based workflows are welcome too.

    Read the article

  • Is it important to dispose SolidBrush and Pen?

    - by Joe
    I recently came across this VerticalLabel control on CodeProject. I notice that the OnPaint method creates but doesn't dispose Pen and SolidBrush objects. Does this matter, and if so how can I demonstrate whatever problems it can cause? EDIT This isn't a question about the IDisposable pattern in general. I understand that callers should normally call Dispose on any class that implements IDisposable. What I want to know is what problems (if any) can be expected when GDI+ object are not disposed as in the above example. It's clear that, in the linked example, OnPaint may be called many times before the garbage collector kicks in, so there's the potential to run out of handles. However I suspect that GDI+ internally reuses handles in some circumstances (for example if you use a pen of a specific color from the Pens class, it is cached and reused). What I'm trying to understand is whether code like that in the linked example will be able to get away with neglecting to call Dispose. And if not, to see a sample that demonstrated what problems it can cause. I should add that I have very often (including the OnPaint documentation on MSDN) seen WinForms code samples that fail to dispose GDI+ objects.

    Read the article

  • Is Git ready to be recommended to my boss?

    - by Mike Weller
    I want to recomment Git to my boss as a new source control system, since we're stuck in the 90s with VSS (ouch), but are the tools and 3rd party support good enough yet? Specifically I'm talking about GUI front-ends similar to TortoiseSVN, decent visual diff/merge support, as well as stuff like email commit notifications and general support from 3rd parties like IDEs and build systems. Even though this will be used by programmers, we really need this kind of stuff in our team. I don't want to leave everyone stuck with a new tool, and even a new source control paradigm (distributed), with nothing but a command-line app and some online tutorials. This would be a step backwards. So what do you think... is Git ready? What decent tools exist for Git and what third party development apps support it? EDIT: My original question was pretty vague so I'm updating it to specifically ask for a list of available tools and 3rd party support for Git. Maybe we can get a community wiki post with a list of stuff. I also do not consider 'use subversion' to be an adequate answer. There are other reasons to use a distributed source control system other than offline editing - private and cheap branches being one of them.

    Read the article

  • Passing IDisposable objects through constructor chains

    - by Matt Enright
    I've got a small hierarchy of objects that in general gets constructed from data in a Stream, but for some particular subclasses, can be synthesized from a simpler argument list. In chaining the constructors from the subclasses, I'm running into an issue with ensuring the disposal of the synthesized stream that the base class constructor needs. Its not escaped me that the use of IDisposable objects this way is possibly just dirty pool (plz advise?) for reasons I've not considered, but, this issue aside, it seems fairly straightforward (and good encapsulation). Codes: abstract class Node { protected Node (Stream raw) { // calculate/generate some base class properties } } class FilesystemNode : Node { public FilesystemNode (FileStream fs) : base (fs) { // all good here; disposing of fs not our responsibility } } class CompositeNode : Node { public CompositeNode (IEnumerable some_stuff) : base (GenerateRaw (some_stuff)) { // rogue stream from GenerateRaw now loose in the wild! } static Stream GenerateRaw (IEnumerable some_stuff) { var content = new MemoryStream (); // molest elements of some_stuff into proper format, write to stream content.Seek (0, SeekOrigin.Begin); return content; } } I realize that not disposing of a MemoryStream is not exactly a world-stopping case of bad CLR citizenship, but it still gives me the heebie-jeebies (not to mention that I may not always be using a MemoryStream for other subtypes). It's not in scope, so I can't explicitly Dispose () it later in the constructor, and adding a using statement in GenerateRaw () is self-defeating since I need the stream returned. Is there a better way to do this? Preemptive strikes: yes, the properties calculated in the Node constructor should be part of the base class, and should not be calculated by (or accessible in) the subclasses I won't require that a stream be passed into CompositeNode (its format should be irrelevant to the caller) The previous iteration had the value calculation in the base class as a separate protected method, which I then just called at the end of each subtype constructor, moved the body of GenerateRaw () into a using statement in the body of the CompositeNode constructor. But the repetition of requiring that call for each constructor and not being able to guarantee that it be run for every subtype ever (a Node is not a Node, semantically, without these properties initialized) gave me heebie-jeebies far worse than the (potential) resource leak here does.

    Read the article

  • Opaque tenant identification with SQL Server & NHibernate

    - by Anton Gogolev
    Howdy! We're developing a nowadays-fashionable multi-tenanted SaaS app (shared database, shared schema), and there's one thing I don't like about it: public class Domain : BusinessObject { public virtual long TenantID { get; set; } public virtual string Name { get; set; } } The TenantID is driving me nuts, as it has to be accounted for almost everywhere, and it's a hassle from security standpoint: what happens if a malicious API user changes TenantID to some other value and will mix things up. What I want to do is to get rid of this TenantID in our domain objects altogether, and to have either NHibernate or SQL Server deal with it. From what I've already read on the Internets, this can be done with CONTEXT_INFO (here's a NHibernatebased implementation), NHibernate filters, SQL Views and with combination thereof. Now, my requirements are as follows: Remove any mentions of TenantID from domain objects ...but have SQL Server insert it where appropriate (I guess this is achieved with default constraints) ...and obviously provide support for filtering based on this criteria, so that customers will never see each other's data If possible, avoid SQL Server views. Have a solution which plays nicely with NHibernate, SQL Servers' MARS and general nature of SaaS apps being highly concurrent What are your thoughts on that?

    Read the article

  • Response.Redirect not firing due to code to prevent re-submission

    - by Marco
    I have an event which needs to contact some third party providers before performing a redirect (think 'final payment page on ecommerce site') and hence has some lag associated with its processing. It is very important that these third party providers are not contacted more than once, and sometimes impatient users may try and refresh the page (hence re-submitting the data). The general code structure is: If Session("orderStatus") <> 'processing' Then Session("orderStatus") = 'processing' DoThirdPartyStuffThatTakesSomeTime() Response.Redirect("confirmationPage.asp", True) End If The problem is, if the user refreshes the page, the response.redirect does not happen (even though the rest of the code will run before the redirect from the original submission). It seems that the new submission creates a new thread for the browser which takes precedence - it skips this bit of code obviously to prevent the third party providers being contacted a second time, and since there is no redirect, just comes back to the same page. The whole second submission may have completed before the first submission has finished its job. Any help on how I can still ignore all of the subsequent submissions of the page, but still make the redirect work...? Thanks

    Read the article

  • Android Plugin in Eclipse 3.5 on Ubuntu 64bit got problems with properties

    - by Zordid
    Hi there! I got a huge problem with the Android Development Tools ADT running in Eclipse Galileo (3.5.1) on Ubuntu 9.10, 64bit. On this platform, I do not manage to see any property edit dialogs for layout properties. E.g. the one where you can select a string resource ID for text fields, or a drawable ID for image fields or backgrounds. Whenever I click on the ... button next to the property value - nothing happens, except this button disappears. Properties with a list of possible values, e.g. "wrap_content" or "fill_parent" are displayed in a dropdown box directly in the properties field. On a different system I work in a Windows environment with Eclipse 3.4 and the same ADT: no problems whatsoever, everything works fine, the dialogs come perfectly. Does anyone know what to do here? Where's the problem? Why does Eclipse not tell me that something goes wrong? Thanks! NEW DISCOVERIES: I found out that it might not even be an Android problem, but a general Eclipse problem that I can see with all version (Ganymede, Galileo, Helios) on my Linux (Ubuntu) system. It must be a simple UI problem: the button with ... next to the values does not receive the mouse click!! I managed to see the appropriate dialogs to edit the property values by doubleclicking the button - crazy, strange, ugly behavior! But why on earth does nobody else know about this problem - I cannot find anything else on the net about it! Could it be related to this strange "GDK native window problem" on Gnome? HELP!

    Read the article

  • Ways to gain a deeper understanding of programming concepts?

    - by MrPlow
    I'm a marketer and have been messing around in PHP/MySQL for years. Recently (the last several months) I've been making my own scripts/programs in Python and I've really enjoyed the whole problem solving process. I've read(skimmed) some books and understand the basics of OOP, polymorphism, etc.. I have a general interest in AI and Natural Language in particular but it seems these things require a masters in Computer Science. My knowledge of math is poor. The last class I took was calculus, and I've forgotten the majority of it. Basically I'm looking for things to learn that will help me think in a more analytic way, and maybe see solutions where I didn't before. Improving my ability to program in Python would be nice too. I don't need to learn a specific language or something for employment, just enjoyment. Although my work often involves web development so some utility would be nice. I don't like learning concepts by just reading them. I need to apply them, even if the examples are contrived. A recommendation of a couple good books or other resources would be nice. :) Apologies if this is too vague/misplaced...

    Read the article

  • Caching Authentication Data

    - by PartlyCloudy
    Hi, I'm currently implementing a REST web service using CouchDB and RESTlet. The RESTlet layer is mainly for authentication and some minor filtering of the JSON data served by CouchDB: Clients <= HTTP = [ RESTlet <= HTTP = CouchDB ] I'm using CouchDB also to store user login data, because I don't want to add an additional database server for that purpose. Thus, each request to my service causes two CouchDB requests conducted by RESTlet (auth data + "real" request). In order to keep the service as efficent as possible, I want to reduce the number of requests, in this case redundant requests for login data. My idea now is to provide a cache (i.e.LRU-Cache via LinkedHashMap) within my RESTlet application that caches login data, because HTTP caching will probabily not be enough. But how do I invalidate the cache data, once a user changes the password, for instance. Thanks to REST, the application might run on several servers in parallel, and I don't want to create a central instance just to cache login data. Currently, I save requested auth data in the cache and try to auth new requests by using them. If a authentication fails or there is now entry available, I'll dispatch a GET request to my CouchDB storage in order to obtain the actual auth data. So in a worst case, users that have changed their data will perhaps still be able to login with their old credentials. How can I deal with that? Or what is a good strategy to keep the cache(s) up-to-date in general? Thanks in advance.

    Read the article

  • mysql/algorithm: Weighting an average to accentuate differences from the mean

    - by Sai Emrys
    This is for a new feature on http://cssfingerprint.com (see /about for general info). The feature looks up the sites you've visited in a database of site demographics, and tries to guess what your demographic stats are based on that. All my demgraphics are in 0..1 probability format, not ratios or absolute numbers or the like. Essentially, you have a large number of data points that each tend you towards their own demographics. However, just taking the average is poor, because it means that by adding in a lot of generic data, the number goes down. For example, suppose you've visited sites S0..S50. All except S0 are 48% female; S0 is 100% male. If I'm guessing your gender, I want to have a value close to 100%, not just the 49% that a straight average would give. Also, consider that most demographics (i.e. everything other than gender) does not have the average at 50%. For example, the average probability of having kids 0-17 is ~37%. The more a given site's demographics are different from this average (e.g. maybe it's a site for parents, or for child-free people), the more it should count in my guess of your status. What's the best way to calculate this? For extra credit: what's the best way to calculate this, that is also cheap & easy to do in mysql?

    Read the article

  • Querying a database using Cocoa.

    - by S1syphus
    Hello everybody. Before I start a disclaimer, I should add a little disclaimer, that I am relatively new to Cocoa development and C in general. However I do have a copy of 'Cocoa Programming for Mac OS X 3rd edition' by Aaron Hillegass, which I am working through and using as a base, if anybody has a copy I am using the 'AmaZone' example on page 346 as a template and base. I trying to develop a small client app that takes a search string then displays results from a database accordingly. The database will contain a: list of files, their location, description & creation date, so for the moment the field number and types will remain the same. After looking around on SO, I saw something like: NSURL *myURL = [NSURL URLWithString:@"http://www.myserver.com/results.php"]; NSArray *sqlResults = [[NSArray alloc] initWithContentsOfURL:myURL]; I've worked with php before, so my current thinking after seeing this is create a php script on the server that queries the database, and creates an XML output. And with the XML response, just parse it. Would this be ok? as is there any major pitfalls anybody can see, that I can't. I know there are some database bundles, I've had a look at BaseTen for Postgres, but being relatively new to this, didn't want to get in over my head. Or if anybody else has any other suggestions and ideas, they would be greatly appreciated.

    Read the article

  • Android - Temporal & Ancestral Navigation with ViewPager & Fragments

    - by rascuache
    I'm trying to work out the best way to implement the 'ancestral' and 'temporal' navigation (utilising the up button and back buttons), for a music player I'm working on. Currently, the user is presented with a viewpager, and can page between three main fragments (ArtistMain, AlbumMain and SongMain). Upon choosing an item inside that view, a fragment transaction occurs, and the viewpager goes out of view, replaced by a new fragment (AlbumSub, Songsub or player, depending on where the user came from). The user can then navigate deeper, until a song is chosen, and then they are taken to the 'player' screen. I guess the question is: How do I implement all of this conditional navigation? I'm fairly new to android and programming in general, and I just can't seem to come up with an efficient way to achieve this. At the moment, as each fragment is brought into view, the app is checking to see where the user just came from, and then determines where the user should be taken if back or home is called. This means I have a booleans like "fromArtistMain", "fromAlbumSub", and I'm checking for things like "fromSongSub && fromPlayer".. it's all turning into a bit of a mess. I've drawn a diagram (in paint, sorry!!), to depict the navigation I'm trying to achieve. The yellow represents the 'up' button press, the red is the 'back' button press, and blue is just normal navigation. The green arrows are meant to represent the view paging: Any advice is welcome. It might take something really simple that I've just overlooked. Thanks for your time.

    Read the article

  • When to choose which machine learning classifier?

    - by LM
    Suppose I'm working on some classification problem. (Fraud detection and comment spam are two problems I'm working on right now, but I'm curious about any classification task in general.) How do I know which classifier I should use? (Decision tree, SVM, Bayesian, logistic regression, etc.) In which cases is one of them the "natural" first choice, and what are the principles for choosing that one? Examples of the type of answers I'm looking for (from Manning et al.'s "Introduction to Information Retrieval book": http://nlp.stanford.edu/IR-book/html/htmledition/choosing-what-kind-of-classifier-to-use-1.html): a. If your data is labeled, but you only have a limited amount, you should use a classifier with high bias (for example, Naive Bayes). [I'm guessing this is because a higher-bias classifier will have lower variance, which is good because of the small amount of data.] b. If you have a ton of data, then the classifier doesn't really matter so much, so you should probably just choose a classifier with good scalability. What are other guidelines? Even answers like "if you'll have to explain your model to some upper management person, then maybe you should use a decision tree, since the decision rules are fairly transparent" are good. I care less about implementation/library issues, though. Also, for a somewhat separate question, besides standard Bayesian classifiers, are there 'standard state-of-the-art' methods for comment spam detection (as opposed to email spam)? [Not sure if stackoverflow is the best place to ask this question, since it's more machine learning than actual programming -- if not, any suggestions for where else?]

    Read the article

  • State Animation on ListBox ItemTemplate

    - by Peanut
    I have a listbox which reads from Observable collection, and is ItemTemplate'ed: <DataTemplate x:Key="DataTemplate1"> <Grid x:Name="grid" Height="47.333" Width="577" Opacity="0.495"> <Image HorizontalAlignment="Left" Margin="10.668,8,0,8" Width="34" Source="{Binding ImageLocation}"/> <TextBlock Margin="56,8,172.334,8" TextWrapping="Wrap" Text="{Binding ApplicationName}" FontSize="21.333"/> <Grid x:Name="grid1" HorizontalAlignment="Right" Margin="0,10.003,-0.009,11.33" Width="26" Opacity="0" RenderTransformOrigin="0.5,0.5"> <Image HorizontalAlignment="Stretch" Margin="0" Source="image/downloads.png" Stretch="Fill" MouseDown="Image_MouseDown" /> </Grid> </Grid> </DataTemplate> <ListBox x:Name="searchlist" Margin="8" ItemTemplate="{DynamicResource DataTemplate1}" ItemsSource="{Binding SearchResults}" SelectionChanged="searchlist_SelectionChanged" ItemContainerStyle="{DynamicResource ListBoxItemStyle1}" /> In general, my question is "What is the easiest way to do Animation on Particular Items in this listbox As they are selected? Basically the image inside the "grid1" will be setting its opacity to 1, slowly. I would prefer to use states, but I do not know of any way to just tell blend and xaml to "When a selected item is changed, change the image opacity to 1 over a period of .3 seconds". Infact, I have been doing this in the .cs file using the VisualStateManager. Also, there is another issue. When the selected index is changed, we goto the CS file and look at SelectedItem. SelectedItem returns an instance of the Object in which it was bound to (The object inside the observable collection), and NOT an instance of the DataTemplate/ListItem etc. So how am I able to pull the correct image out of this list? State animation with VisualStateManager I can handle fine if its just normal things, but when it comes to generated listboxes' items, I'm lost. Thanks

    Read the article

  • Unit testing that an event is raised in C#, using reflection

    - by Thomas
    I want to test that setting a certain property (or more generally, executing some code) raises a certain event on my object. In that respect my problem is similar to http://stackoverflow.com/questions/248989/unit-testing-that-an-event-is-raised-in-c, but I need a lot of these tests and I hate boilerplate. So I'm looking for a more general solution, using reflection. Ideally, I would like to do something like this: [TestMethod] public void TestWidth() { MyClass myObject = new MyClass(); AssertRaisesEvent(() => { myObject.Width = 42; }, myObject, "WidthChanged"); } For the implementation of the AssertRaisesEvent, I've come this far: private void AssertRaisesEvent(Action action, object obj, string eventName) { EventInfo eventInfo = obj.GetType().GetEvent(eventName); int raisedCount = 0; Action incrementer = () => { ++raisedCount; }; Delegate handler = /* what goes here? */; eventInfo.AddEventHandler(obj, handler); action.Invoke(); eventInfo.RemoveEventHandler(obj, handler); Assert.AreEqual(1, raisedCount); } As you can see, my problem lies in creating a Delegate of the appropriate type for this event. The delegate should do nothing except invoke incrementer. Because of all the syntactic syrup in C#, my notion of how delegates and events really work is a bit hazy. How to do this?

    Read the article

  • Algorithm for count-down timer that can add on time

    - by Person
    I'm making a general timer that has functionality to count up from 0 or count down from a certain number. I also want it to allow the user to add and subtract time. Everything is simple to implement except for the case in which the timer is counting down from some number, and the user adds or subtracts time from it. For example: (m_clock is an instance of SFML's Clock) float Timer::GetElapsedTime() { if ( m_forward ) { m_elapsedTime += m_clock.GetElapsedTime() - m_elapsedTime; } else { m_elapsedTime -= m_elapsedTime - m_startingTime + m_clock.GetElapsedTime(); } return m_elapsedTime; } To be a bit more clear, imagine that the timer starts at 100 counting down. After 10 seconds, the above function would look like 100 -= 100 - 100 + 10 which equals 90. If it was called after 20 more seconds it would look like 90 -= 90 - 100 + 30 which equals 70. This works for normal counting, but if the user calls AddTime() ( just m_elapsedTime += arg ) then the algorithm for backwards counting fails miserably. I know that I can do this using more members and keeping track of previous times, etc. but I'm wondering whether I'm missing some implementation that is extremely obvious. I'd prefer to keep it as simple as possible in that single operation.

    Read the article

  • regenerating url in cf9/Coldbox

    - by faheem7860
    Hi I am wondering if there is a way to regenerate the URL when any page is loaded in coldbox/CF9 when using event.buildLink ? Currently I get http://cawksd05.codandev.local:8080/entries/editor when using event.buildlink. But the correct url should have /index.cfm added to it as shown below: /index.cfm/entries/editor Is there a way to set this once and where does this get set as I am confused where to set this for all my pages so that /index.cfm gets added the the url prefix when I do an event.Buildlink. Thanks Faheem // General Properties setUniqueURLS(false); setAutoReload(false); // Base URL if( len(getSetting('AppMapping') ) lte 1){ setBaseURL("http://#cgi.HTTP_HOST#/index.cfm"); } else{ setBaseURL("http://#cgi.HTTP_HOST#/#getSetting('AppMapping')#/index.cfm"); } // Your Application Routes formatConstraints = {format="(xml|json)"}; addRoute(pattern="/api/:format/tasks/completed",handler="tasksAPI",action="list",constraints=formatConstraints,completed=true); addRoute(pattern="/api/:format/tasks",handler="tasksAPI",action="list",constraints=formatConstraints); addRoute(pattern="/api/:format?",handler="tasksAPI",action="invalid"); addRoute(pattern="/tasks/list/:status?",handler="tasks",action="index"); addRoute(pattern=":handler/:action?");

    Read the article

< Previous Page | 274 275 276 277 278 279 280 281 282 283 284 285  | Next Page >