Search Results

Search found 1421 results on 57 pages for 'arbitrary'.

Page 33/57 | < Previous Page | 29 30 31 32 33 34 35 36 37 38 39 40  | Next Page >

  • Applying a function to an arbitrarily long list of arguments

    - by alphomega
    I want to create a function apply that takes a function with an arbitrary amount of arguments as well as a list of integers, and returns the result of the function (Where each integer in the list is an argument in order. I was thinking something like: apply :: ([Int] -> Int) -> [Int] -> Int apply f x:xs = apply (f x) xs apply f [] = f But I know this won't work because the type signature is wrong - the function doesn't take a list of ints, it just takes some amount of int arguments. Additionally, when I get to the base case the f argument to apply should actually be an integer, violating the type signature anyway. Does anyone know how to deal with this sort of problem?

    Read the article

  • Why is generated XAML spitting out namespaces that are not asked for?

    - by Matt Holmes
    I have a very simple XAML form, that has one namespace definition. For some reason, when Visual Studio processes that XAML file in to it's component .g.cs, it's sticking a bunch of namespace definitions at the top that I have not asked for in the XAML, or the code behind, and they are namespaces that no longer exist in my project. Thus the project is failing to compile. Why is Visual Studio sticking arbitrary namespace 'using' statements in my generated XAML .g.cs files? It's caused my entire project to break. Not one time did this .xaml file ever reference the namespaces in question, so it's doubly annoying.

    Read the article

  • Detect if camera is capturing in Flash

    - by Ben
    I'm having trouble with Camera.getCamera() in Flash AS3. If there are multiple camera drivers, it does not necessarily pick the correct one. If the default is the correct, the program works fine; however, if another driver is selected as the default then LED on the webcam does not come on and no video is captured. I can cycle through the available cams and select an arbitrary one. I don't, however, know how to determine if the selected camera is correct. It is not returning null. I considered using camera.currentFPS, but it's not clear when this gets updated. I'm really struggling to determine dynamically which camera will do the trick!

    Read the article

  • taking intersection of N-many lists in python

    - by user248237
    what's the easiest way to take the intersection of N-many lists in python? if I have two lists a and b, I know I can do: a = set(a) b = set(b) intersect = a.intersection(b) but I want to do something like a & b & c & d & ... for an arbitrary set of lists (ideally without converting to a set first, but if that's the easiest / most efficient way, I can deal with that.) I.e. I want to write a function intersect(*args) that will do it for arbitrarily many sets efficiently. What's the easiest way to do that? EDIT: My own solution is reduce(set.intersection, [a,b,c]) -- is that good? thanks.

    Read the article

  • Group MySQL Data into Arbitrarily Sized Time Buckets

    - by Eric J.
    How do I count the number of records in a MySQL table based on a timestamp column per unit of time where the unit of time is arbitrary? Specifically, I want to count how many record's timestamps fell into 15 minute buckets during a given interval. I understand how to do this in buckets of 1 second, 1 minute, 1 hour, 1 day etc. using MySQL date functions, e.g. SELECT YEAR(datefield) Y, MONTH(datefield) M, DAY(datefield) D, COUNT(*) Cnt FROM mytable GROUP BY YEAR(datefield), MONTH(datefield), DAY(datefield) but how can I group by 15 minute buckets?

    Read the article

  • In C#, is there any way to try multiple Regexes on string to see which one matches first?

    - by Matt
    Let's say I have an arbitrary list of regexes (IList<Regex> lst; for example). Is there any way to find out which one matches first? Of course there is the straightforward solution of trying each one on the string and seeing which match has the lowest index, but this could be inefficient on long strings. Of course I can go back and pull the strings back out of each regex (Regex.ToString()) and concatenate them all together ("(regex1)|(regex2)|(regex3)"), but I find this to be an ugly solution, especially since it does not even indicate which regex was matched.

    Read the article

  • Nicely printing/showing a binary tree in Haskell

    - by nicole
    I have a tree data type: data Tree a b = Branch b (Tree a b) (Tree a b) | Leaf a ...and I need to make it an instance of Show, without using deriving. I have found that nicely displaying a little branch with two leaves is easy: instance (Show a, Show b) => Show (Tree a b) where show (Leaf x) = show x show (Branch val l r) = " " ++ show val ++ "\n" ++ show l ++ " " ++ show r But how can I extend a nice structure to a tree of arbitrary size? It seems like determining the spacing would require me to know just how many leaves will be at the very bottom (or maybe just how many leaves there are in total) so that I can allocate all the space I need there and just work 'up.' I would probably need to call a size function. I can see this being workable, but is that making it harder than it is?

    Read the article

  • Looking for solution to persist rows sequence in a database table that allow efficient reordering at

    - by Chau Chee Yang
    I have a database table. There is a field name "Sequence" that indicate sequence when user presents the rows in report or grid visually. When the rows are retrieved and presented in a grid, there are few UI gadget that allow user to reorder the rows arbitrary. The new sequence will be persist in database table when user commit the changes. Here are some UI operations: Move to first Move to last Move up 1 row Move down 1 row multi-select rows and move up or down multi-select rows and drag to new position For operation like "Move to first" or "Move to Last", it usually involve many rows and the sequence those rows would need to be updated accordingly. This may not be efficient enough at runtime. It is a common practice to use INTEGER as sequence's data type. Other solution is using "DOUBLE" or "FLOAT" that could overcome the mass update of row sequence but we will face problem if we reach the limit of precision.

    Read the article

  • C++ fixed point library?

    - by uj2
    I am looking for a free C++ fixed point library (Mainly for use with embedded devices, not for arbitrary precision math). Basically, the requirements are: No unnecessary runtime overhead: whatever can be done at compile time, should be done at compile time. Ability to transparently switch code between fixed and floating point, with no inherent overhead. Fixed point math functions. There's no much point using fixed point if you need to cast back and forth in order to take a square root. Small footprint. Any suggestions?

    Read the article

  • Multiple children in single form in rails

    - by CaptnCraig
    I have a model that has an arbitrary number of children entities. For simplicity lets call the entities Orders and Items. I would like to have a create Orders form where I input the order information, as well as add as many items as I want. If I click the "Add another item" button, a new set of form elements will be added to input the new data, amounts, etc.. I could hack this out in pure javascript, but I'm pretty sure there has to be a more magical, railsish way to do it, maybe with a partial view or something. I'm just a little too new to rails to know what it is. What is the best way to dynamically add the new form elements, and then to access them in the create controller?

    Read the article

  • A RecursiveParentChildIterator -- like the RecursiveDirectoryIterator

    - by Stephen J. Fuhry
    There are tons of examples of using the RecursiveIterator to flatten a tree structure.. but what about using it to explode a tree structure? Is there an elegant way to use this, or some other SPL library to recursively build a tree (read: turn a flat array into array of arbitrary depth) given a table like this: SELECT id, parent_id, name FROM my_tree EDIT: You know how you can do this with Directories? $it = new RecursiveDirectoryIterator("/var/www/images"); foreach(new RecursiveIteratorIterator($it) as $file) { echo $file . PHP_EOL; } .. What if you could do something like this: $it = new RecursiveParentChildIterator($result_array); foreach(new RecursiveIteratorIterator($it) as $group) { echo $group->name . PHP_EOL; // this would contain all of the children of this group, recursively $children = $group->getChildren(); } :END EDIT

    Read the article

  • Reject (Hard 404) ASP.NET MVC-style URLs

    - by James D
    Hi, ASP.NET MVC web app that exposes "friendly" URLs: http://somesite.com/friendlyurl ...which are rewritten (not redirected) to ASP.NET MVC-style URLs under the hood: http://somesite.com/Controller/Action The user never actually sees any ASP.NET MVC style URLS. If he requests one, we hard 404 it. ASP.NET MVC is (in this app) an implementation detail, not a fundamental interface. My question: how do you examine an arbitrary incoming URL and determine whether or not that URL matches a defined ASP.NET MVC path? For extra credit: how do you do it from inside an ASP.NET-style IHttpModule, where you're getting invoked upstream from the ASP.NET MVC runtime? Thanks!

    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

  • Changing the color of a Rebol button

    - by Dave Matuszek
    I want to ask multiple choice questions in Rebol. Possible answers will be on buttons. I want to turn a button red when it is clicked and it is the wrong answer. When the correct button is pressed, I want to proceed to the next question. I can change the color of a box (mybox/color: red show mybox). I can set up a toggle with two colors (but I can't change it based on the result of an arbitrary test (is the answer correct?). It seems like there is probably a simple way to change the color of a button, without having to create my own button-like face objects. Isn't there?

    Read the article

  • What wording in the C++ standard allows static_cast<non-void-type*>(malloc(N)); to work?

    - by ben
    As far as I understand the wording in 5.2.9 Static cast, the only time the result of a void*-to-object-pointer conversion is allowed is when the void* was a result of the inverse conversion in the first place. Throughout the standard there is a bunch of references to the representation of a pointer, and the representation of a void pointer being the same as that of a char pointer, and so on, but it never seems to explicitly say that casting an arbitrary void pointer yields a pointer to the same location in memory, with a different type, much like type-punning is undefined where not punning back to an object's actual type. So while malloc clearly returns the address of suitable memory and so on, there does not seem to be any way to actually make use of it, portably, as far as I have seen.

    Read the article

  • Function Composition in C++

    - by Channel72
    There are a lot of impressive Boost libraries such as Boost.Lambda or Boost.Phoenix which go a long way towards making C++ into a truly functional language. But is there a straightforward way to create a composite function from any 2 or more arbitrary functions or functors? If I have: int f(int x) and int g(int x), I want to do something like f . g which would statically generate a new function object equivalent to f(g(x)). This seems to be possible through various techniques, such as those discussed here. Certainly, you can chain calls to boost::lambda::bind to create a composite functor. But is there anything in Boost which easily allows you to take any 2 or more functions or function objects and combine them to create a single composite functor, similar to how you would do it in a language like Haskell?

    Read the article

  • Efficient synchronization of querying an array of resources

    - by Erel Segal Halevi
    There is a list of N resources, each of them can be queried by at most a single thread at a time. There are serveral threads that need to do the same thing at approximately the same time: query each of the resources (each thread has a different query), in arbitrary order, and collect the responses. If each thread loops over the resources in the same order, from 0 to N-1, then they will probably have to wait for each other, which is not efficient. I thought of letting the threads loop over the resources in a random permutation, but this seems too complex and also not so efficient, for example, for 2 resources and 2 threads, in half the cases they will choose the same order and wait for each other. Is there a simple and more efficient way to solve this?

    Read the article

  • Revisions: algorithm and data structure

    - by SODA
    Hi, I need ideas for structuring and processing data with revisions. For example, I have a database of objects (e.g. cars). Each object has a number of properties, which can be arbitrary, so there's no a set schema to describe these objects. These objects are probably saved as key-value pairs. Now I need to change property of an object. I don't want to completely rewrite it - I want to be able to go back and see history of changes to these properties, that's why I want to add new property and keep the old one (so I guess a timestamp would do the job of telling which property is the latest). At the same time I want to be able to get info about any object in a snap, with only latest versions of each of the properties. Any ideas what would be the best approach? At least please point me in the right direction. Thanks!

    Read the article

  • signed angle between two 3d vectors with same origin within the same plane? recipe?

    - by Advanced Customer
    Was looking through the web for an answer but it seems like there is no clear recipe for it. What I need is a signed angle of rotation between two vectors Va and Vb lying within the same 3D plane and having the same origin knowing that: the plane contatining both vectors is an arbitrary and is not parallel to XY or any other of cardinal planes Vn - is a plane normal both vectors along with the normal have the same origin O = { 0, 0, 0 } Va - is a reference for measuring the left handed rotation at Vn The angle should be measured in such a way so if the plane would be XY plane the Va would stand for X axis unit vector of it. I guess I should perform a kind of coordinate space transformation by using the Va as the X-axis and the cross product of Vb and Vn as the Y-axis and then just using some 2d method like with atan2() or something. Any ideas? Formulas?

    Read the article

  • How do I measure distances in an image?

    - by Ram Bhat
    Let's say we have an image like so Let's say we've already used filters and an edge detection algorithm in this pic. Now my goal is to measure distances (NOT actual distances, distance can be in any arbitrary unit) . eg: How do I find the length of the hall? (until the window) Or the height of the bookshelves? How exactly do you place the "scale" and measure. I'm looking for ideas. However it would help if the answers were in terms of OpenCV.

    Read the article

  • How to order results based on number of search term matches?

    - by Travis
    I am using the following tables in mysql to describe records that can have multiple searchtags associated with them: TABLE records ID title desc TABLE searchTags ID name TABLE recordSearchTags recordID searchTagID To SELECT records based on arbitrary search input, I have a statement that looks sort of like this: SELECT recordID FROM recordSearchTags LEFT JOIN searchTags ON recordSearchTags.searchTagID = searchTags.ID WHERE searchTags.name LIKE CONCAT('%','$search1','%') OR searchTags.name LIKE CONCAT('%','$search2','%') OR searchTags.name LIKE CONCAT('%','$search3','%') OR searchTags.name LIKE CONCAT('%','$search4','%'); I'd like to ORDER this resultset, so that rows that match with more search terms are displayed in front of rows that match with fewer search terms. For example, if a row matches all 4 search terms, it will be top of the list. A row that matches only 2 search terms will be somewhere in the middle. And a row that matches just one search term will be at the end. Any suggestions on what is the best way to do this? Thanks!

    Read the article

  • make mongrel_rails (localhost:3000) visible to a virtual machine

    - by Max Williams
    I develop rails in ubuntu and i just set up a virtualbox windows xp virtual machine for IE testing. I'd like to be able to run mongrel_rails in ubuntu and then jump into the vm to check it out, so i can jump back, make a change, jump into the vm again, reload the page and test it, etc. Is this possible? In this sort of situation in the past i've had to set up an apache server on my dev machine and run mongrel under that, in order to get an externally visible (ie visible to my local network) ip address that i then paste into the address bar of IE in the vm. Is this really necessary? Is there a simpler way? Can i do something with my /etc/hosts or sites-available files to just make up some arbitrary network address which points to localhost:3000 in ubuntu? Or something? thanks, max

    Read the article

  • Choosing a design pattern for a class that might change it's internal attributes

    - by the_drow
    I have a class that holds arbitrary state and it's defined like this: class AbstractFoo { }; template <class StatePolicy> class Foo : public StatePolicy, public AbstractFoo { }; The state policy contains only protected attributes that represent the state. The state might be the same for multiple behaviors and they can be replaced at runtime. All Foo objects have the same interface to abstract the state itself and to enable storing Foo objects in containers. I would like to find the least verbose and the most maintainable way to express this.

    Read the article

  • How can I limit the number of connections to an mssql server from my tomcat deployed java applicatio

    - by CJ
    Hi, I have an application that is deployed on tomcat on server A and sends queries to a huge variety of mssql databases on an server B. I am concerned that my application could overload this mssql database server and would like some way to preventing it making requests to connect to any database on that server if some arbitrary number of connections were already in existence and unclosed. I am looking at using connection pooling but am under the impression that this will only pool connections to a specific database on the mssql server, I want to control the total of these combined connections that will occur to many different databases (incidentally I can only find out the names of individual db's dynamically as they change day to day). Will connection pooling take care of this for me, are am I looking at this from the wrong perspective? I have no access to the configuration of the mssql server. Links to tutorials or working examples of your suggested solution are most welcome! Thanks, Caroline

    Read the article

  • Programmatic Website Screen Shots

    - by Ian
    I'm checking into the available methods for programmatically taking screenshots of an arbitrary website. For example, Facebook: http://clicktoverify.truste.com/pvr.php?page=validate&url=www.facebook.com&sealid=102 Salesforce.com: http://clicktoverify.truste.com/pvr.php?page=validate&companyName=Salesforce.com,%20Inc.&sealid=102&internal=true On that page you'll see they have a screenshot of the referenced site. What are my options for getting these kinds of screenshots in an automated fashion? I'm primarily working with PHP, but am open to all suggestions. Thanks!

    Read the article

< Previous Page | 29 30 31 32 33 34 35 36 37 38 39 40  | Next Page >