Search Results

Search found 2995 results on 120 pages for 'logical operators'.

Page 82/120 | < Previous Page | 78 79 80 81 82 83 84 85 86 87 88 89  | Next Page >

• Flipping issue when interpolating Rotations using Quaternions

  - by uhuu

  I use slerp to interpolate between two quaternions representing rotations. The resulting rotation is then extracted as Euler angles to be fed into a graphics lib. This kind of works, but I have the following problem; when rotating around two (one works just fine) axes in the direction of the green arrow as shown in the left frame here the rotation soon jumps around to rotate from the opposite site to the opposite visual direction, as indicated by the red arrow in the right frame. This may be logical from a mathematical perspective (although not to me), but it is undesired. How could I achieve an interpolation with no visual flipping and changing of directions when rotating around more than one axis, following the green arrow at all times until the interpolation is complete? Thanks in advance.

  Read the article

• Should I use DTOs as my data models in MVVM?

  - by JonC

  I'm currently working on what will be my first real foray into using MVVM and have been reading various articles on how best to implement it. My current thoughts are to use my data models effectively as data transfer objects, make them serializable and have them exist on both the client and server sides. It seems like a logical step given that both object types are really just collections of property getters and setters and another layer in between seems like complete overkill. Obviously there would be issues with INotifyPropertyChanged not working correctly on the server side as there is no ViewModel to which to communicate, but as long as we are careful about constructing our proper domain model objects from data models in the service layer and not dealing the the data models on the server side I don't think it should be a big issue. I haven't found too much info about this approach in my reading, so I would like to know if this is a pretty standard thing, is this just assumed to be the de facto way of doing MVVM in a multi-tier environment? If I've got completely the wrong idea about things then thoughts on other approaches would be appreciated too.

  Read the article

• Allow for modular development while still running in same JVM?

  - by Marcus

  Our current app runs in a single JVM. We are now splitting up the app into separate logical services where each service runs in its own JVM. The split is being done to allow a single service to be modified and deployed without impacting the entire system. This reduces the need to QA the entire system - just need to QA the interaction with the service being changed. For inter service communication we use a combination of REST, an MQ system bus, and database views. What I don't like about this: REST means we have to marshal data to/from XML DB views couple the systems together which defeats the whole concept of separate services MQ / system bus is added complexity There is inevitably some code duplication between services You have set up n JBoss server configurations, we have to do n number of deployments, n number of set up scripts, etc, etc. Is there a better way to structure an internal application to allow modular development and deployment while allowing the app to run in a single JVM (and achieving the associated benefits)?

  Read the article

• Good excuses NOT to use version control

  - by Kent Fredric

  This question may seem backwards to all logical reasoning, but I encountered a team member who was working on a side project out of the main tree, and had decided ( rephrased ) I'm the only developer, we don't need version control, that's stupid Now personally, the idea horrifies me, and I can't for one justify it. So now my stance is clear, I want some legitimate answers why somebody can excuse themselves from using version control. The default answers will of course be "there is no excuse". Not what I want to see. If you can't see an excuse, then just don't post. ( Feel free to downmod excuses others post that are illegitimate/bad and give reasoning )

  Read the article

• Declaring pointers; asterisk on the left or right of the space between the type and name?

  - by GenTiradentes

  I've seen mixed versions of this in a lot of code. (This applies to C and C++, by the way.) People seem to declare pointers in one of two ways, and I have no idea which one is correct, of if it even matters. The first way it to put the asterisk adjacent the type name, like so: someType* somePtr; The second way is to put the asterisk adjacent the name of the variable, like so: someType *somePtr; This has been driving me nuts for some time now. Is there any standard way of declaring pointers? Does it even matter how pointers are declared? I've used both declarations before, and I know that the compiler doesn't care which way it is. However, the fact that I've seen pointers declared in two different ways leads me to believe that there's a reason behind it. I'm curious if either method is more readable or logical in some way that I'm missing.

  Read the article

• Visual C++ doesn't operator<< overload

  - by PierreBdR

  I have a vector class that I want to be able to input/output from a QTextStream object. The forward declaration of my vector class is: namespace util { template <size_t dim, typename T> class Vector; } I define the operator<< as: namespace util { template <size_t dim, typename T> QTextStream& operator<<(QTextStream& out, const util::Vector<dim,T>& vec) { ... } template <size_t dim, typename T> QTextStream& operator>>(QTextStream& in,util::Vector<dim,T>& vec) { .. } } However, if I ty to use these operators, Visual C++ returns this error: error C2678: binary '<<' : no operator found which takes a left-hand operand of type 'QTextStream' (or there is no acceptable conversion) A few things I tried: Originaly, the methods were defined as friends of the template, and it is working fine this way with g++. The methods have been moved outside the namespace util I changed the definition of the templates to fit what I found on various Visual C++ websites. The original friend declaration is: friend QTextStream& operator>>(QTextStream& ss, Vector& in) { ... } The "Visual C++ adapted" version is: friend QTextStream& operator>> <dim,T>(QTextStream& ss, Vector<dim,T>& in); with the function pre-declared before the class and implemented after. I checked the file is correctly included using: #pragma message ("Including vector header") And everything seems fine. Doesn anyone has any idea what might be wrong?

  Read the article

• unexpected result from gnu sort

  - by funkycat

  when I try to sort the following text file 'input': test1 3 test3 2 test 4 with the command sort input the output is exactly the input. Here is the output of od -bc input : 0000000 164 145 163 164 061 011 063 012 164 145 163 164 063 011 062 012 t e s t 1 \t 3 \n t e s t 3 \t 2 \n 0000020 164 145 163 164 011 064 012 t e s t \t 4 \n 0000027 It's just a tab separated file with two columns. When I do sort -k 2 The output changes to test3 2 test1 3 test 4 which is what I would expect. But if I do sort -k 1 nothing changes with respect to the input, whereas I would expect 'test' to sort before 'test1'. Finally, if I do cat input | cut -f 1 | sort I get test test1 test3 as expected. Is there a logical explanation for this? What exactly is sort supposed to do by default, something like: sort -k 1 ? My version of sort: sort (GNU coreutils) 7.4

  Read the article

• Can FileOutputStream() take a relative path as an argument

  - by Ankur

  I am creating a FileOutputStream object. It takes a file or String as an argument in its constructor. My question is, can I give it a relative URL as an argument for the location of a file, it doesn't seem to work, but I am trying to work out if this is possible at all (if not I will stop trying). If it is not possible, how can I (from a servlet) get the absolute path (on the filesystem, not the logical URL) to the current location in such a way that I can pass that to the constructor. Part of my problem is that my dev box is Windows but I will publish this to a Unix box, so the paths cannot be the same i.e. on Windows C:/.... and on unix /usr/...

  Read the article

• Generate syntax tree for simple math operations

  - by M28

  I am trying to generate a syntax tree, for a given string with simple math operators (+, -, *, /, and parenthesis). Given the string "1 + 2 * 3": It should return an array like this: ["+", [1, ["*", [2,3] ] ] ] I made a function to transform "1 + 2 * 3" in [1,"+",2,"*",3]. The problem is: I have no idea to give priority to certain operations. My code is: function isNumber(ch){ switch (ch) { case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': case '.': return true; break; default: return false; break; } } function generateSyntaxTree(text){ if (typeof text != 'string') return []; var code = text.replace(new RegExp("[ \t\r\n\v\f]", "gm"), ""); var codeArray = []; var syntaxTree = []; // Put it in its on scope (function(){ var lastPos = 0; var wasNum = false; for (var i = 0; i < code.length; i++) { var cChar = code[i]; if (isNumber(cChar)) { if (!wasNum) { if (i != 0) { codeArray.push(code.slice(lastPos, i)); } lastPos = i; wasNum = true; } } else { if (wasNum) { var n = Number(code.slice(lastPos, i)); if (isNaN(n)) { throw new Error("Invalid Number"); return []; } else { codeArray.push(n); } wasNum = false; lastPos = i; } } } if (wasNum) { var n = Number(code.slice(lastPos, code.length)); if (isNaN(n)) { throw new Error("Invalid Number"); return []; } else { codeArray.push(n); } } })(); // At this moment, codeArray = [1,"+",2,"*",3] return syntaxTree; } alert('Returned: ' + generateSyntaxTree("1 + 2 * 3"));

  Read the article

• How to allow for modular development while still running in same JVM?

  - by Marcus

  Our current app runs in a single JVM. We are now splitting up the app into separate logical services where each service runs in its own JVM. The split is being done to allow a single service to be modified and deployed without impacting the entire system. This reduces the need to QA the entire system - just need to QA the interaction with the service being changed. For interservice communication we use a combination of REST, an MQ system bus, and database views. What I don't like about this: REST means we have to marshal data to/from XML DB views couple the systems together which defeats the whole concept of separate services MQ / system bus is added complexity There is inevitably some code duplication between services You have set up n JBoss server configurations, we have to do n number of deployments, n number of set up scripts, etc, etc. Is there a better way to structure an internal application to allow modular development and deployment while allowing the app to run in a single JVM (and achieving the associated benefits)?

  Read the article

• Use interface between model and view in ASP.NET MVC

  - by Icerman

  Hi, I am using asp.net MVC 2 to develop a site. IUser is used to be the interface between model and view for better separation of concern. However, things turn to a little messy here. In the controller that handles user sign on: I have the following: IUserBll userBll = new UserBll(); IUser newUser = new User(); newUser.Username = answers[0].ToString(); newUser.Email = answers[1].ToString(); userBll.AddUser(newUser); The User class is defined in web project as a concrete class implementing IUser. There is a similar class in DAL implementing the same interface and used to persist data. However, when the userBll.AddUser is called, the newUser of type User can't be casted to the DAL User class even though both Users class implementing the interface (InvalidCastException). Using conversion operators maybe an option, but it will make the dependency between DAL and web which is against the initial goal of using interface. Any suggestions?

  Read the article

• Need help with ruby radiant cms

  - by AnimalCode

  I have some hidden pages like this: /staff John Bob Mike In all this pages i have extended content, like photo, bio and additional info. I make this, to have logical structure and quick edit without editing radiant code. My question is, how i can with base radius functional get access to this pages in this code: <r:find url="/staff"> <r:children:each by="title" order="asc"> <r:title /> </r:children:each> </r:find>

  Read the article

• 'Lexical' scoping of type parameters in C#

  - by leppie

  I have 2 scenarios. This fails: class F<X> { public X X { get; set; } } error CS0102: The type 'F' already contains a definition for 'X' This works: class F<X> { class G { public X X { get; set; } } } The only logical explanation is that in the second snippet the type parameter X is out of scope, which is not true... Why should a type parameter affect my definitions in a type? IMO, for consistency, either both should work or neither should work. Any other ideas? PS: I call it 'lexical', but it probably is not not the correct term.

  Read the article

• looking to streamline my RSS feed mashup

  - by Mark Cejas

  Hello crafty developers, I have aggregated RSS feeds from various sources with RSSowl, fetching directly from the social mention API. The RSS feeds are categorized into the following major categories: blogs, news, twitter, Q&A and social networking sites. Each major category is nested with a common group of RSS feeds that represent a particular client/brand ontology. Merging these feeds into the RSSowl reader application, allows me to conduct and save refined search queries (from the aggregated data) into a single file - that I can then tag and further segment for analysis. This scheme is utilized for my own research needs and has helped me considerably. However, I find this RSS mashup scheme kinda clumsy, it requires quite a bit of time to initially organize all of the feeds and I would like to be able to do further natural language processing to the data as well as eventually be able to rank the collected list of URL's into some order of media prominence - right I don't want to pay the ridiculous radian6 web analytics fees, when my intuition is telling me that with a bit of 'elbow grease' I can maybe leverage some available resources online to develop a functional low scale web mining application and get some good intelligence from it. I am now starting to learn a little about computer science - my background is in physical science/statistics so is my thinking in the right track? So, I guess I am imagining an application that allows me to query in a refined manner. A manner that allows me to search for keyword combinations, applying AND/OR operators, selectively focus my queries into particular sources - like a collection of blogs or twitter, or social networking communities, then save the results of my queries into a structured format that can then be manipulated and explored. Am I dreaming? I just had to get all of this out. any bit of advice and insight would be hugely appreciated. my best, Mark

  Read the article

• Multiple inequality conditions (range queries) in NoSQL

  - by pableu

  Hi, I have an application where I'd like to use a NoSQL database, but I still want to do range queries over two different properties, for example select all entries between times T1 and T2 where the noiselevel is smaller than X. On the other hand, I would like to use a NoSQL/Key-Value store because my data is very sparse and diverse, and I do not want to create new tables for every new datatype that I might come across. I know that you cannot use multiple inequality filters for the Google Datastore (source). I also know that this feature is coming (according to this). I know that this is also not possible in CouchDB (source). I think I also more or less understand why this is the case. Now, this makes me wonder.. Is that the case with all NoSQL databases? Can other NoSQL systems make range queries over two different properties? How about, for example, Mongo DB? I've looked in the Documentation, but the only thing I've found was the following snippet in their docu: Note that any of the operators on this page can be combined in the same query document. For example, to find all document where j is not equal to 3 and k is greater than 10, you'd query like so: db.things.find({j: {$ne: 3}, k: {$gt: 10} }); So they use greater-than and not-equal on two different properties. They don't say anything about two inequalities ;-) Any input and enlightenment is welcome :-)

  Read the article

• What is the algorithm used by the memberwise equality test in .NET structs?

  - by Damian Powell

  What is the algorithm used by the memberwise equality test in .NET structs? I would like to know this so that I can use it as the basis for my own algorithm. I am trying to write a recursive memberwise equality test for arbitrary objects (in C#) for testing the logical equality of DTOs. This is considerably easier if the DTOs are structs (since ValueType.Equals does mostly the right thing) but that is not always appropriate. I would also like to override comparison of any IEnumerable objects (but not strings!) so that their contents are compared rather than their properties. This has proven to be harder than I would expect. Any hints will be greatly appreciated. I'll accept the answer that proves most useful or supplies a link to the most useful information. Thanks.

  Read the article

• Why does sh/bash set command line parameter values when trying to set environment variable?

  - by Touko

  A question on basics : While tuning environment variables for a program launched from a script, I ended up with somewhat strange behaviour with sh (which seems to be actually linked to bash) : variable setting seems to mess up with command-line parameters. Could somebody explain why does this happen? A simple script: #! /bin/sh # Messes with $1 ?? set ANT_OPTS=-Xmx512M export ANT_OPTS # Works # export ANT_OPTS=-Xmx512M echo "0 = $0" echo "1 = $1" When I run this with the upper alternative (set + export), the result is as following: $ ./test.sh foo 0 = ./test.sh 1 = ANT_OPTS=-Xmx512M But with lower alternative (export straight), the result is as I supposed: $ ./test.sh foo 0 = ./test.sh 1 = foo There is surely logical explanation, I just haven't figured it out yet. Somebody who does have idea? br, Touko

  Read the article

• How do I optimize this postfix expression tree for speed?

  - by Peter Stewart

  Thanks to the help I received in this post: I have a nice, concise recursive function to traverse a tree in postfix order: deque <char*> d; void Node::postfix() { if (left != __nullptr) { left->postfix(); } if (right != __nullptr) { right->postfix(); } d.push_front(cargo); return; }; This is an expression tree. The branch nodes are operators randomly selected from an array, and the leaf nodes are values or the variable 'x', also randomly selected from an array. char *values[10]={"1.0","2.0","3.0","4.0","5.0","6.0","7.0","8.0","9.0","x"}; char *ops[4]={"+","-","*","/"}; As this will be called billions of times during a run of the genetic algorithm of which it is a part, I'd like to optimize it for speed. I have a number of questions on this topic which I will ask in separate postings. The first is: how can I get access to each 'cargo' as it is found. That is: instead of pushing 'cargo' onto a deque, and then processing the deque to get the value, I'd like to start processing it right away. I don't yet know about parallel processing in c++, but this would ideally be done concurrently on two different processors. In python, I'd make the function a generator and access succeeding 'cargo's using .next(). But I'm using c++ to speed up the python implementation. I'm thinking that this kind of tree has been around for a long time, and somebody has probably optimized it already. Any Ideas? Thanks

  Read the article

• Django many-to-many relationship to self with extra data, how do I select from a certain direction?

  - by Jake

  I have some hierarchical data where each Set can have many members and can belong to more than one Set(group) Here are the models: class Set(models.Model): ... groups = models.ManyToManyField('self', through='Membership', symmetrical=False) members = models.ManyToManyField('self', through='Membership', symmetrical=False) class Membership(models.Model): group = models.ForeignKey( Set, related_name='Members' ) member = models.ForeignKey( Set, related_name='Groups' ) order = models.IntegerField( default=-1 ) I want to know how to get all the members or all the groups for a Set instance. I think I can do it as follows, but it's not very logical, can anyone tell me what's going on and how I should be doing it? # This gives me a set of Sets # Which seems to be the groups this Set belongs to set_instance.set_set.all() # These give me a set of Memberships, not Sets set_instance.Members.all() set_instance.Groups.all() # These they both return a set of Sets # which seem to be the members of this one set_instance.members.all() set_instance.groups.all()

  Read the article

• Download office document without the web server trying to render it

  - by Dan Revell

  I'm trying to download an InfoPath template that's hosted on SharePoint. If I hit the url in internet explorer it asks me where to save it and I get the correct file on my disk. If I try to do this programmatically with WebClient or HttpWebRequest then I get HTML back instead. How can I make my request so that the web server returns the actual xsn file and doesn't try to render it in html. If internet explorer can do this then it's logical to think that I can too. I've tried setting the Accept property of the request to application/x-microsoft-InfoPathFormTemplate but that hasn't helped. It was a shot in the dark.

  Read the article

• Getting Parent Layout in Qt

  - by Austin

  Hi, quick question. Is there any way to (easily) retrieve the parent layout of a widget in Qt? PS: QObject::parent() won't work, for logical reasons. EDIT: I'm positive the widget has a parent layout, because I added it to a layout earlier in the code. Now, I have many other layouts in the window and while it is possible for me to keep track of them, I just want to know if there is an easy and clean way to get the parent layout. EDIT2: Sorry, "easy and clean" was probably not the best way of putting. I meant using the Qt API. EDIT3: I'm adding the widget to the layout like this: QHBoxLayout* layout = new QHBoxLayout; layout-addWidget(button);

  Read the article

• How to preserve object identity across different VMs

  - by wheleph

  To be specific let me illustrate the question with Spring http-remoting example. Suppose we have such implementation of a simple interface: public SearchServiceImpl implements SearchService { public SearchJdo processSearch(SearchJdo search) { search.name = "a funky name"; return search; } } SearchJdo is itself a simple POJO. Now when we call the method from a client through http-remoting we'll get: public class HTTPClient { public static void main(final String[] arguments) { final ApplicationContext context = new ClassPathXmlApplicationContext( "spring-http-client-config.xml"); final SearchService searchService = (SearchService) context.getBean("searchService"); SearchJdo search = new SearchJdo(); search.name = "myName"; // this method actually returns the same object it gets as an argument SearchJdo search2 = searchService.processSearch(search); System.out.println(search == search2); // prints "false" } } The problem is that the search objects are different because of serializaton although from logical prospective they are the same. The question is whether there are some technique that allows to support or emulate object identity across VMs.

  Read the article

• Why not speed up testing by using function dependency graph?

  - by Maltrap

  It seems logical to me that if you have a dependency graph of your source code (tree showing call stack of all functions in your code base) you should be able to save a tremendous amount of time doing functional and integration tests after each release. Essentially you will be able to tell the testers exactly what functionality to test as the rest of the features remain unchanged from a source code point of view. If for instance you change a spelling mistake in once piece of the code, there is no reason to run through your whole test script again "just in case" you introduced a critical bug. My question, why are dependency trees not used in software engineering and if you use them, how do you maintain them? What tools are available that generate these trees for C# .NET, C++ and C source code?

  Read the article

• barebones sort algorithm

  - by user309322

  i have been asked to make a simple sort aglorithm to sort a random series of 6 numbers into numerical order. However i have been asked to do this using "Barebones" a theoretical language put forward in the Book Computer Science an overview. Some information on the language can be found here http://www.brouhaha.com/~eric/software/barebones/ Just to clarify i am a student teacher and have been doing anaysis on "mini-programing languages" and their uses in a teaching environment, i suggested to my tutor that i look at barebones and asked what sort of exmaple program i should write . He suggested a simple sort algorithm. Now since looking at the language i cant understand how i can do this without using arrays and if statements. The code to swap the value of variables would be while a not 0 do; incr Aux1; decr a; end; while b not 0 do; incr Aux2 decr b end; while Aux1 not 0 do; incr a; decr Aux1; end; while Aux2 not 0 do; incr b; decr Aux2; end; however the language does not provide < or operators

  Read the article

• Any useful suggestions to figure out where memory is being free'd in a Win32 process?

  - by LeopardSkinPillBoxHat

  An application I am working with is exhibiting the following behaviour: During a particular high-memory operation, the memory usage of the process under Task Manager (Mem Usage stat) reaches a peak of approximately 2.5GB (Note: A registry key has been set to allow this, as usually there is a maximum of 2GB for a process under 32-bit Windows) After the operation is complete, the process size slowly starts decreasing at a rate of 1MB per second. I am trying to figure out the easiest way to quickly determine who is freeing this memory, and where it is being free'd. I am having trouble attaching a memory profiler to my code, and I don't particularly want to override the new/delete operators to track the allocations/deallocations (IOW, I want to do this without re-compiling my code). Can anyone offer any useful suggestions of how I could do this via the Visual Studio debugger? Update I should also mention that it's a multi-threaded application, so pausing the application and analysing the call stack through the debugger is not the most desirable option. I considered freezing different threads one at a time to see if the memory stops reducing, but I'm fairly certain this will cause the application to crash.

  Read the article

< Previous Page | 78 79 80 81 82 83 84 85 86 87 88 89  | Next Page >