Search Results

Search found 4503 results on 181 pages for 'logical operator'.

Page 121/181 | < Previous Page | 117 118 119 120 121 122 123 124 125 126 127 128  | Next Page >

  • Get a list of documents from Mongo DB

    - by Andrei Neagu
    Hello, I want to do something like this: List<int> fff = new List<int>(); fff.Add(1); fff.Add(2); fff.Add(5); Mongo m = new Mongo(); m.Connect(); var dataBase = m.GetDatabase("database"); var collection = dataBase.GetCollection("coll"); IMongoQuery queryable = collection.AsQueryable(); MongoQueryProvider prov = new MongoQueryProvider(collection); var query = new MongoQuery(prov); var ffppp = from p221 in query where fff.Contains((int)p221["oid"]) select p221; This throws this error : The method 'Contains' could not be converted into a constant. I saw that mongo has an operator $in. Does any one know how can I use it from c#? (http://www.mongodb.org/display/DOCS/Advanced+Queries) Thanks

    Read the article

  • Python/Tkinter Audio Player

    - by Nicholas Quirk
    Hey everyone reading this, I've recently got into doing GUI development with Python. Tkinter seems like the easiest and most logical choice starting out. I did a little with wxPython but it was more sophisticated than what I needed. Anyway, I'm developing a media player. Right now it's a simple window with a button to load .wav files. The problem is I would like to implement a pause button now. But, when playing a audio file the GUI isn't accessible again (no buttons can be pushed) till the file is done playing. How can I make the GUI dynamic while an audio file is playing? I was thinking this maybe be because I'm using PyAudio, and their implementation doesn't allow this. Anyway, thanks for any advice before hand.

    Read the article

  • match at the beginning of any line, including the first

    - by JoelFan
    According the the Perl documentation on regexes: By default, the "^" character is guaranteed to match only the beginning of the string ... Embedded newlines will not be matched by "^" ... You may, however, wish to treat a string as a multi-line buffer, such that the "^" will match after any newline within the string ... you can do this by using the /m modifier on the pattern match operator. The "after any newline" part means that it will only match at the beginning of the 2nd and subsequent lines. What if I want to match at the beginning of any line (1st, 2nd, etc.)?

    Read the article

  • How does sizeof calculate the size of structures

    - by Gearoid Murphy
    I know that a char and an int are calculated as being 8 bytes on 32 bit architectures due to alignment, but I recently came across a situation where a structure with 3 shorts was reported as being 6 bytes by the sizeof operator. Code is as follows: #include <iostream> using namespace std ; struct IntAndChar { int a ; unsigned char b ; }; struct ThreeShorts { unsigned short a ; unsigned short b ; unsigned short c ; }; int main() { cout<<sizeof(IntAndChar)<<endl; // outputs '8' cout<<sizeof(ThreeShorts)<<endl; // outputs '6', I expected this to be '8' return 0 ; } Compiler : g++ (Debian 4.3.2-1.1) 4.3.2. This really puzzles me, why isn't alignment enforced for the structure containing 3 shorts?

    Read the article

  • std::map default value for build-in type

    - by Qifa Zhao
    Recently, I was confused by the std::map operator[] function. In the MSDN library, it says: "If the argument key value is not found, then it is inserted along with the default value of the data type." I tryed to search much more exactly explanation for this issue. For example here: std::map default value In this page, Michael Anderson said that "the default value is constructed by the default constructor(zero parameter constructor)". Now my quest comes to this:"what the default value for the build-in type?". Was it compiler related? Or is there a standard for this issue by the c++ stardard committee? I did a test on visual studio 2008 for the "int" type, and found the "int" type is construted with the value 0.

    Read the article

  • Objective-C convention to prevent "local declaration hides instance variable" warning

    - by Nippysaurus
    Is there a common convention for dealing with these scenarios? The following code is what I am using .. -(id) initWithVariableName: (NSString*)variableName withComparisonValue:(NSString*)comparisonValue { self.mustExist = NO; self.reverseCondition = NO; self.regularExpression = NO; self.variableName = variableName; self.comparisonValue = comparisonValue; return self; } But I am getting "Local declaration of 'variableName' hides instance variable" and the same for "comparisonValue". The function signature seems logical to me, but surely there must be a more "acceptable" standard which will still make sense and be accurate but not generate annoying warnings?

    Read the article

  • Why will this code compile using ifort compiler and not when using gfortran compiler? Help!

    - by CuriousCompiler
    I'm rewriting some code to make a program compile with the gfortran compiler as opposed to ifort compiler I usually use. The code follows: _Subroutine SlideBits (WORD, BITS, ADDR) Implicit None Integer(4) WORD Integer(4) BITS Integer(4) ADDR Integer(4) ADDR1 ADDR1 = 32 - ADDR WORD = (WORD .And. (.Not.ISHFT(1,ADDR1))) .Or. ISHFT(BITS,ADDR1) End_ When I compile the above code using the gfortran compiler, I recieve this error: WORD = (WORD .And. (.Not.ISHFT(1,ADDR1))) .Or. ISHFT(BITS,ADDR1) Error: Operand of .NOT. operator at (1) is INTEGER(4) All three of the variables coming into the subroutine are integers. I've looked around a bit and the gfortran wiki states that the gfortran compiler should be able to handle logical statments being applied to integer values. Several other sites I've visited either quote from the gnu wiki or agree with it. This is the first time I've seen this error as the Intel Fortran compiler (ifort) I normally use compiles cleanly.

    Read the article

  • Encrypt text using a number

    - by Adam Matan
    Project Euler I have recently begun to solve some of the Project Euler riddles. I found the discussion forum in the site a bit frustrating (most of the discussions are closed and poorly-threaded), So I have decided to publish my Python solutions on launchpad for discussion. The problem is that it seems quite unethical to publish these solutions, as it would let other people gain reputation without doing the programming work, which the site deeply discourages. My Encryption problem I want to encrypt my answers so that only those who have already solved the riddles can see my code. The logical key would be the answer to the riddle, which is always numeric. In order to prevent brute-force attacks on my answers, I want to find an encryption algorithm that takes a significantly long time (few seconds) to run. Do you know any such algorithm? I would fancy a Python package, which I can attach to the code, over an external program that might have portability issues. Thanks, Adam

    Read the article

  • C# implicit conversions

    - by Chris Boden
    Hello, I'm currently working on an application where I need to load data from an SQL database and then assign the retrieved values into the properties of an object. I'm doing this by using reflection since the property names and column names are the same. However, many of the properties are using a custom struct type that is basically a currency wrapper for the decimal type. I have defined an implicit conversion in my struct: public static implicit operator Currency(decimal d) { return new Currency(d); } This works fine when I use it in code. However, when I have this: foreach (PropertyInfo p in props) { p.SetValue(this, table.Rows[0][p.Name], null); } It throws an ArgumentException stating that it cannot convert from System.Decimal to Currency. I'm confused since it works fine in any other circumstance.

    Read the article

  • how to get the size of a C global array into an assembly program written for the avr architecture co

    - by johannes
    I have a .c file with the following uint8_t buffer[32] I have a .S file where I want to do the following cpi r29, buffer+sizeof(buffer) The second argument for cpi muste be an imidiate value not a location. But unfortunetly sizeof() is a c operator. Both files, are getting compiled to seperate object files and linked afterwards. If I do avr-objdump -x file.c. Amongst other things, I get the size of the buffer. So it is already available in the object file. How do I access the size of the buffer in my assembly file at compile time?

    Read the article

  • Storing multiple checkbox values in database

    - by Madjokr
    Hi, I want to store multiple column values in table.Lets take a example .. What are your favourite colors? the choices can be red,blue,green, orange. So lets assume, the user selects atleast 2 values. Is there any way to store the multiple values in table. I have implemented by concatinating choices of users in a column in the table. I later found that it is a bad practise. Currently i can think of using Bitwise operator and habtm. What are the different ways for storing multiple choices values in table? If I am implementing in rails, What is the best way to implement this with OOP concepts? Is there any builtin options in rails?

    Read the article

  • Python threads all executing on a single core

    - by Rob Lourens
    I have a Python program that spawns many threads, runs 4 at a time, and each performs an expensive operation. Pseudocode: for object in list: t = Thread(target=process, args=(object)) # if fewer than 4 threads are currently running, t.start(). Otherwise, add t to queue But when the program is run, Activity Monitor in OS X shows that 1 of the 4 logical cores is at 100% and the others are at nearly 0. Obviously I can't force the OS to do anything but I've never had to pay attention to performance in multi-threaded code like this before so I was wondering if I'm just missing or misunderstanding something. Thanks.

    Read the article

  • How does a programmer think?

    - by Gordon Potter
    This may be a hopelessly vague question. But I am interested to hear whatever logical thought processes people go through when learning a new concept or trying to get their brain around code they might not have ever seen before. Basically, what general steps does one take to to break down problems and what does it take to "get it"? If you were to diagram a flowchart of how your mental process works when you look at code or try to solve a problem what might it look like? What common references, tips, and mental assumptions do you find useful in problem solving? How is this different between different domains? For example in what ways is a web programmer's thought process similar or different from a traditional desktop app developer's process?

    Read the article

  • Finding recurrence relations of an algorithm

    - by Roarke
    I'm reading my algorithms text book, and I'm reading about recurrence relations and finding the algorithms big O complexity. I run across this line "In the case of the merge-sort algorithm, we get the recurrence equation: t(n) = b if n < 2 = 2t(n/2) +bn if n >= 2 for b > 0 my response was "how the heck did we know that?!?!" So i'm wondering if there is a systematic approach, or just a logical way of getting these recurrence relations from the algorithms can some one explain where the b and the two 2's come from?

    Read the article

  • How to read from a method that returns a filehandle in perl?

    - by Ryan Thompson
    I have an object with a method that returns a filehandle, and I want to read from that handle. The following doesn't work, because the right angle bracket of the method call is interpreted as the closing angle bracket of the input reader: my $input = <$object->get_handle()>; That gets parsed as: my $input = ( < $object- > ) get_handle() >; which is obviously a syntax error. Is there any way I can perform a method call within an angle operator, or do I need to break it into two steps like this? my $handle = $object->get_handle(); my $input = <$handle>;

    Read the article

  • Optimal password salt length

    - by Juliusz Gonera
    I tried to find the answer to this question on Stack Overflow without any success. Let's say I store passwords using SHA-1 hash (so it's 160 bits) and let's assume that SHA-1 is enough for my application. How long should be the salt used to generated password's hash? The only answer I found was that there's no point in making it longer than the hash itself (160 bits in this case) which sounds logical, but should I make it that long? E.g. Ubuntu uses 8-byte salt with SHA-512 (I guess), so would 8 bytes be enough for SHA-1 too or maybe it would be too much?

    Read the article

  • matlab noninteger step indexing

    - by rlbond
    So, I have a vector: k = 1:100; And I want to take 19 elements from it, which are roughly equally-spaced. So I write this: m = k(1:(99/18):end); This works great, except for a tiny problem: Warning: Integer operands are required for colon operator when used as index m = 1 7 12 18 23 29 34 40 45 51 56 62 67 73 78 84 89 95 100 Now, I understand why this comes up, but I'd like to get rid of that warning. Is there a "right" way to do this without a warning?

    Read the article

  • Does std::multiset guarntee insertion order?

    - by Naveen
    I have a std::multiset which stores elements of class A. I have provided my own implementation of operator< for this class. My question is if I insert two equivalent objects into this multiset is their order guaranteed? For example, first I insert a object a1 into the set and then I insert an equivalent object a2 into this set. Can I expect the a1 to come before a2 when I iterate through the set? If no, is there any way to achieve this using multiset?

    Read the article

  • Binding multiple arrays for WHERE IN in PostgreSQL

    - by Alec
    So I want to prepare a query something like: SELECT id FROM users WHERE (branch, cid) IN $1; But I then need to bind a variable length list of arrays like (('a','b'),('c','d')) to it. How do I go about doing this? I've tried using ANY but can't seem to get the syntax right. Cheers, Alec Edit: After some fiddling around, this is valid syntactically: SELECT id FROM users WHERE (branch, cid) = ANY ($1::text[][]); and then binding the string '{{a,b},{c,d}}' to $1 but throws the error "operator does not exist: record = text". Changing 'text' to 'record' then throws "input of anonymous composite types is not implemented". Any ideas?

    Read the article

  • How can I match at the beginning of any line, including the first, with a Perl regex?

    - by JoelFan
    According the the Perl documentation on regexes: By default, the "^" character is guaranteed to match only the beginning of the string ... Embedded newlines will not be matched by "^" ... You may, however, wish to treat a string as a multi-line buffer, such that the "^" will match after any newline within the string ... you can do this by using the /m modifier on the pattern match operator. The "after any newline" part means that it will only match at the beginning of the 2nd and subsequent lines. What if I want to match at the beginning of any line (1st, 2nd, etc.)? EDIT: OK, it seems that the file has BOM information (3 chars) at the beginning and that's what's messing me up. Any way to get ^ to match anyway? EDIT: So in the end it works (as long as there's no BOM), but now it seems that the Perl documentation is wrong, since it says "after any newline"

    Read the article

  • Google Datastore low-level api query by key property

    - by Keyur
    I'm using the low-level google datastore api and I want to query by the key property and another property (let's call it category). I need to query based on a list of keys for which I'll use the IN operator. I know that the max. number of values you can provide for the IN clause is 30. I have 2 questions: Does the limit of 30 IN values apply to the key property as well? Do I need to create a composite index on {_key_ + category} or just on {category} for this query? Thanks, Keyur

    Read the article

  • construct test environment for web application on PC - directory issues

    - by ernie
    I have a site that physically has this directory structure. -public_html --conf > contains file conf.php -SiteFiles -LiveSite > contains file ConfLive.php Directory public_html/conf/ contains a file called conf.php this file contains the following include include_once('/home/mydir/SiteFiles/LiveSite/conf/ConfLive.iphp'); I want to copy this application to test PC to test it. Test PC uses XAMPP Apache. "Root" directory on the test machine is: C:\xampp\htdocs\ My questions: 1. Where is logical path "/home/mydir/" defined? 2. What steps should I take to get this to work on my test machine preferably by server configuration and not changing application. Thanks. (PS maybe this question is better posed at Server Overflow site.)

    Read the article

  • Pros and Cons of Different macro function / inline methods in C

    - by Robert S. Barnes
    According to the C FAQ, there are basically 3 practical methods for "inlining" code in C: #define MACRO(arg1, arg2) do { \ /* declarations */ \ stmt1; \ stmt2; \ /* ... */ \ } while(0) /* (no trailing ; ) */ or #define FUNC(arg1, arg2) (expr1, expr2, expr3) To clarify this one, the arguments are used in the expressions, and the comma operator returns the value of the last expression. or using the inline declaration which is supported as an extension to gcc and in the c99 standard. The do { ... } while (0) method is widely used in the Linux kernel, but I haven't encountered the other two methods very often if at all. I'm referring specifically to multi-statement "functions", not single statement ones like MAX or MIN. What are the pros and cons of each method, and why would you choose one over the other in various situations?

    Read the article

  • Placement new in gcc

    - by Roman Prikhodchenko
    I need to find a workaround for a bug with placement new in g++. I now it was fixed in gcc-4.3 but I have to support versions 4.2 and 4.1. For example, following code compiles with an error "error: no matching function for call to 'operator new(long unsigned int, void*&)" template<class T, template<typename> class Alloc> inline void* type_ctor() { Alloc<T> a; void* p = a.allocate(1); new(p) T; return p; } ..... type_ctor<A, NewAllocator >();

    Read the article

  • What is a Web Framework ? How does it compare with LAMP

    - by Nishant
    I started web development in LAMP/WAMP and it was logical to me . There is a Web Server program called Apache which does the networking part of setting up a service on port 80 ( common port ) . If the request is regular HTML it uses the HTTP headers to transport files .And if the request for the file is a PHP one , it has a mod_php with which Apache invokes the PHP interpreter to process the file and it gives back HTML which is again transferred as usual HTML . Now the question is what is a Web Framework ? I came across Python based website creation and there is Flask . What is a flask , how does it compare with LAMP . Further are DJango / Ruby on Rails different from flask ? Can someone answer me and also give some good places to read on these .Thanks for your answers in advance . Further is things like LAMP slower than the common FRAMEWORKS because they claimn easy deplyment fo web apps .

    Read the article

< Previous Page | 117 118 119 120 121 122 123 124 125 126 127 128  | Next Page >