Search Results

Search found 14000 results on 560 pages for 'include guards'.

Page 142/560 | < Previous Page | 138 139 140 141 142 143 144 145 146 147 148 149  | Next Page >

  • Same memory space being allocated again & again

    - by shadyabhi
    In each loop iteration, variable j is declared again and again. Then why is its address remaining same? Shouldn't it be given some random address each time? Is this compiler dependent? #include<stdio.h> #include<malloc.h> int main() { int i=3; while (i--) { int j; printf("%p\n", &j); } return 0; } Testrun:- shadyabhi@shadyabhi-desktop:~/c$ gcc test.c shadyabhi@shadyabhi-desktop:~/c$ ./a.out 0x7fffc0b8e138 0x7fffc0b8e138 0x7fffc0b8e138 shadyabhi@shadyabhi-desktop:~/c$

    Read the article

  • Indexing with pointer C/C++

    - by Leavenotrace
    Hey I'm trying to write a program to carry out newtons method and find the roots of the equation exp(-x)-(x^2)+3. It works in so far as finding the root, but I also want it to print out the root after each iteration but I can't get it to work, Could anyone point out my mistake I think its something to do with my indexing? Thanks a million :) #include <stdio.h> #include <math.h> #include <malloc.h> //Define Functions: double evalf(double x) { double answer=exp(-x)-(x*x)+3; return(answer); } double evalfprime(double x) { double answer=-exp(-x)-2*x; return(answer); } double *newton(double initialrt,double accuracy,double *data) { double root[102]; data=root; int maxit = 0; root[0] = initialrt; for (int i=1;i<102;i++) { *(data+i)=*(data+i-1)-evalf(*(data+i-1))/evalfprime(*(data+i-1)); if(fabs(*(data+i)-*(data+i-1))<accuracy) { maxit=i; break; } maxit=i; } if((maxit+1==102)&&(fabs(*(data+maxit)-*(data+maxit-1))>accuracy)) { printf("\nMax iteration reached, method terminated"); } else { printf("\nMethod successful"); printf("\nNumber of iterations: %d\nRoot Estimate: %lf\n",maxit+1,*(data+maxit)); } return(data); } int main() { double root,accuracy; double *data=(double*)malloc(sizeof(double)*102); printf("NEWTONS METHOD PROGRAMME:\nEquation: f(x)=exp(-x)-x^2+3=0\nMax No iterations=100\n\nEnter initial root estimate\n>> "); scanf("%lf",&root); _flushall(); printf("\nEnter accuracy required:\n>>"); scanf("%lf",&accuracy); *data= *newton(root,accuracy,data); printf("Iteration Root Error\n "); printf("%d %lf \n", 0,*(data)); for(int i=1;i<102;i++) { printf("%d %5.5lf %5.5lf\n", i,*(data+i),*(data+i)-*(data+i-1)); if(*(data+i*sizeof(double))-*(data+i*sizeof(double)-1)==0) { break; } } getchar(); getchar(); free(data); return(0); }

    Read the article

  • How can I get cmake to find my boost installation

    - by BD at Rivenhill
    I have installed the most recent version of boost in /usr/local (with includes in /usr/local/boost and libraries in /usr/local/lib/boost) and I am now attempting to install Wt from source, but cmake (version 2.6) can't seem to find the boost installation. It tries to give helpful suggestions about setting BOOST_DIR and Boost_LIBRARYDIR, but I haven't been able to get it to work by tweaking these variables. The most recent error message that I get is that it can't find the libraries, but it seems to indicate that it is using "/usr/local/include" for the include path, which isn't correct (and I can't seem to fix it). Does anybody have a solution for this off the top of their head, or do I need to go mucking around inside cmake to figure it out?

    Read the article

  • sort std::list case sensitive elements

    - by Dave18
    #include <list> #include <string> using std::string; using std::list; int main() { list <string> list_; list_.push_back("C"); list_.push_back("a"); list_.push_back("b"); list_.sort(); } does sort() function sort the elements according to their character codes? I want the result here to be a b C after the sorting is done.

    Read the article

  • Searching for range overlaps in Ruby hashes

    - by mbm
    Say you have the following Ruby hash, hash = {:a => [[1, 100..300], [2, 200..300]], :b => [[1, 100..300], [2, 301..400]] } and the following functions, def overlaps?(range, range2) range.include?(range2.begin) || range2.include?(range.begin) end def any_overlaps?(ranges) # This calls to_proc on the symbol object; it's syntactically equivalent to # ranges.sort_by {|r| r.begin} ranges.sort_by(&:begin).each_cons(2).any? do |r1, r2| overlaps?(r1, r2) end end and it's your desire to, for each key in hash, test whether any range overlaps with any other. In hash above, I would expect hash[:a] to make me mad and hash[:b] to not. How is this best implemented syntactically?

    Read the article

  • Is it a header file or library? in a makefile

    - by gccinac
    I already know the differences between a header file and a library. However, when I'm writing my makefile, I have some difficulties on deciding if I should put something as a dependency of the file or just at the linking rule. For example: I have 2 simple files: main.c: #include <stdio.h> main(){ printf("this is the sine or 90"); sinus(90); } and func.c: #include <math.h> sinus(int num){ return sin(num); } and my makefile is: main: main.o func.o gcc main.o func.o -lm -o main func.o: func.c main.o: main.c Well, my question is why this makefile works and this one doesn't: main: main.o func.o gcc main.o func.o -lm -o main func.o: func.c math.h main.o: main.c

    Read the article

  • Whats the difference between a C++ and a Cocoa Project in Xcode?

    - by david
    I need to work with TagLib for my project. I've created a framework (and I tried using it as a lib) but the compiler cannot find #include < strings on compiling (No such file or Directory). I've created a test C++ project and it #includes < strings just fine. I've looked at the project settings and I cannot find a difference between them. But the standard cocoa projects obviously so not have the search path set to include C++ libraries (Or am I completely getting it wrong?). I've searched for a solution but no one else seems to have run into this problem.

    Read the article

  • When should we use * and & and . and -> ?

    - by uzay95
    Why we are using * character when we are creating button but we aren't adding it to app instance? #include <QApplication> #include <QPushButton> int main(int argc,char *argv[]) { QApplication app(argc,argv); QPushButton *button = new QPushButton("Button Text"); QObject::connect(button,SIGNAL(clicked()),&app,SLOT(quit())); button->show(); return app.exec(); } When should we use * and & and . and - ?

    Read the article

  • how to use replace_regex_copy() from boost::algorithm library?

    - by Vincenzo
    This is my code: #include <string> #include <boost/algorithm/string/regex.hpp> string f(const string& s) { using namespace boost::algorithm; return replace_regex_copy(s, "\\w", "?"); } This is what compiler says: no matching function for call to ‘replace_regex_copy(const std::basic_string<char, std::char_traits<char>, std::allocator<char> >&, std::string, std::string) The link to the library: http://www.boost.org/doc/libs/1_43_0/doc/html/boost/algorithm/replace_regex_copy.html Could anyone please help? Thanks! ps. Boost library is in place, since other functions from it work fine.

    Read the article

  • Why Swift is 100 times slower than C in this image processing test?

    - by xiaobai
    Like many other developers I have been very excited at the new Swift language from Apple. Apple has boasted its speed is faster than Objective C and can be used to write operating system. And from what I learned so far, it's a very type-safe language and able to have precisely control over the exact data type (like integer length). So it does look like having good potential handling performance critical tasks, like image processing, right? That's what I thought before I carried out a quick test. The result really surprised me. Here is a much simplified image alpha blending code snippet in C: test.c: #include <stdio.h> #include <stdint.h> #include <string.h> uint8_t pixels[640*480]; uint8_t alpha[640*480]; uint8_t blended[640*480]; void blend(uint8_t* px, uint8_t* al, uint8_t* result, int size) { for(int i=0; i<size; i++) { result[i] = (uint8_t)(((uint16_t)px[i]) *al[i] /255); } } int main(void) { memset(pixels, 128, 640*480); memset(alpha, 128, 640*480); memset(blended, 255, 640*480); // Test 10 frames for(int i=0; i<10; i++) { blend(pixels, alpha, blended, 640*480); } return 0; } I compiled it on my Macbook Air 2011 with the following command: gcc -O3 test.c -o test The 10 frame processing time is about 0.01s. In other words, it takes the C code 1ms to process one frame: $ time ./test real 0m0.010s user 0m0.006s sys 0m0.003s Then I have a Swift version of the same code: test.swift: let pixels = UInt8[](count: 640*480, repeatedValue: 128) let alpha = UInt8[](count: 640*480, repeatedValue: 128) let blended = UInt8[](count: 640*480, repeatedValue: 255) func blend(px: UInt8[], al: UInt8[], result: UInt8[], size: Int) { for(var i=0; i<size; i++) { var b = (UInt16)(px[i]) * (UInt16)(al[i]) result[i] = (UInt8)(b/255) } } for i in 0..10 { blend(pixels, alpha, blended, 640*480) } The build command line is: xcrun swift -O3 test.swift -o test Here I use the same O3 level optimization flag to make the comparison hopefully fair. However, the resulting speed is 100 time slower: $ time ./test real 0m1.172s user 0m1.146s sys 0m0.006s In other words, it takes Swift ~120ms to processing one frame which takes C just 1 ms. I also verified the memory initialization time in both test code are very small compared to the blend processing function time. What happened?

    Read the article

  • Using * Width & Precision Specifiers With boost::format

    - by John Dibling
    I am trying to use width and precision specifiers with boost::format, like this: #include <boost\format.hpp> #include <string> int main() { int n = 5; std::string s = (boost::format("%*.*s") % (n*2) % (n*2) % "Hello").str(); return 0; } But this doesn't work because boost::format doesn't support the * specifier. Boost throws an exception when parsing the string. Is there a way to accomplish the same goal, preferably using a drop-in replacement?

    Read the article

  • PHP, since upgrading to 5.2.17 getting some warning ?

    - by Jules
    I can't reproduce this on my test server no idea why this is happening, other queries / functions work.. I'm getting this warning PHP Warning: mysql_connect() [<a href='function.mysql-connect'> function.mysql-connect</a>]: Can't connect to MySQL server on '--my isps server--' (10060) in D:\domains\mydomain.com\wwwroot\p hp\_stdfuncs.php on line 191 This function and others like it are having problems (but some are ok), this is my include file... function AddPageError($PageHandle, $Requested) { global $server; global $db; global $user; global $pass; global $sDebug; $con = mysql_connect($server,$user,$pass); I have an include file which sets those variables, as I say they work on other pages and functions.. No idea why ??

    Read the article

  • chained selects with one table

    - by Owen
    I know I am going about this in an unusual way, every tut I've seen uses multiple tables, but due to the way the rest of my site works I would like to create a chained select which operates using a single table. My table structure is: ---------------------- |Catagory|SubCategory| |01|cat1 |subcat1 | |02|cat1 |subcat2 | |03|cat2 |subcat1 | |04|cat2 |subcat2 | ---------------------- The code I have so far looks like: <tr> <td class="shadow"><strong>Category:</strong> </td> <td class="shadow"> <select id="category" name="category" style="width:150px"> <option selected="selected" value="<?php echo $category ?>"><?php echo $category?></option> <?php include('connect.php'); $result1 = mysql_query("SELECT DISTINCT category FROM categories") or die(mysql_error()); while($row = mysql_fetch_array( $result1 )) { $category = $row['category']; echo "<option value='". $row['category'] ."'>". $row['category'] ."</option>"; } ?> </select> </td> </tr> <tr> <td class="shadow"><strong>Sub Category:</strong> </td> <td class="shadow"> <select id="sub_catgory" name="sub_category" style="width:150px;"> <option selected="selected" value="<?php echo $sub_category ?>"><?php echo $sub_category ?></option> <?php include('connect.php'); $result2 = mysql_query("SELECT sub_category FROM categories WHERE ") or die(mysql_error()); while($row = mysql_fetch_array ($result2 )){ echo "<option value='" . $row['sub_category'] . "'>". $row['sub_category']. "</option>"; } ?> </select> </td> </tr> On the second select I am not sure how to state the WHERE clause. I need it to display the subcategories which have the same category as selected in the first select. PART 2 how would I include AJAX in this to preload the data so i don't need to refresh the page. Could someone either help me finish what I've started here or point me to a good tutorial. thanks

    Read the article

  • C++ dynamic type construction and detection

    - by KneLL
    There was an interesting problem in C++, but it concerns more likely architecture. There are many (10, 20, 40, etc) classes that describe some characteristics (mix-in classes), for exmaple: struct Base { virtual ~Base() {} }; struct A : virtual public Base { int size; }; struct B : virtual public Base { float x, y; }; struct C : virtual public Base { bool some_bool_state; }; struct D : virtual public Base { string str; } // .... Primary module declares and exports a function (for simplicity just function declarations without classes): // .h file void operate(Base *pBase); // .cpp file void operate(Base *pBase) { // .... } Any other module can has a code like this: #include "mixins.h" #include "primary.h" class obj1_t : public A, public C, public D {}; class obj2_t : public B, public D {}; // ... void Pass() { obj1_t obj1; obj2_t obj2; operate(&obj1); operate(&obj2); } The question is how to know what the real type of given object in operate() without dynamic_cast and any type information in classes (constants, etc)? Function operate() is used with big array of objects in small time periods and dynamic_cast is too slow for it. And I don't want to include constants (enum obj_type { ... }) because this is not OOP-way. // module operate.cpp void some_operate(Base *pBase) { processA(pBase); processB(pBase); } void processA(A *pA) { } void processB(B *pB) { } I cannot directly pass a pBase to these functions. And it's impossible to have all possible combinations of classes, because I can add new classes just by including new .h files. As one of solutions that comed to mind, in editor application I can use a composite container: struct CompositeObject { vector<Base *pBase> parts; }; But editor does not need a time optimization and can use dynamic_cast for parts to determine the exact type. In operate() I cannot use this solution. So, is it possible to not use a dynamic_cast and type information to solve this problem? Or maybe I should use another architecture?

    Read the article

  • For text-align:right; in TD, why does "style" work and "class" not?

    - by Will Fastie
    If I include this in a table cell: <td style="text-align: right; font-style: italic; color: maroon;">... the contents of the cell are aligned as I expect. If I include the following CSS: .right-notice { text-align: right; font-style: italic; color: maroon; } and this cell: <td class=".right-notice">... the contents of the cell are not right aligned. Why is this? What don't I know? If I change the CSS to replace text-align with float, that works. Thanks.

    Read the article

  • How do I get a array to just count how many numbers there are instead of counting the value of each number?

    - by Chad Loos
    //This is the output of the program *** start of 276 2D Arrays_03.cpp program *** Number Count Total 1 3 3 2 6 9 3 15 24 4 6 30 5 9 39 *** end of 276 2D Arrays_03.cpp program *** #include <iostream> #include <string> #include <iomanip> using namespace std; const int COLUMN_SIZE = 13; int main(void) { const int ROW_SIZE = 3; const int COUNT_SIZE = 5; void countValues(const int[][COLUMN_SIZE], const int, int[]); void display(const int [], const int); int numbers[ROW_SIZE][COLUMN_SIZE] = {{1, 3, 4, 5, 3, 2, 3, 5, 3, 4, 5, 3, 2}, {2, 1, 3, 4, 5, 3, 2, 3, 5, 3, 4, 5, 3}, {3, 4, 5, 3, 2, 1, 3, 4, 5, 3, 2, 3, 5}}; int counts[COUNT_SIZE] = {0}; string choice; cout << "*** start of 276 2D Arrays_03.cpp program ***" << endl; cout << endl; countValues(numbers, ROW_SIZE, counts); display(counts, COUNT_SIZE); cout << endl; cout << endl; cout << "*** end of 276 2D Arrays_03.cpp program ***" << endl << endl; cin.get(); return 0; } // end main() This is the function where I need to count each of the values. I know how to sum rows and cols, but I'm not quite sure of the code to just tally the values themselves. void countValues(const int numbers[][COLUMN_SIZE], const int ROW_SIZE, int counts[]) This is what I have so far. { for (int index = 0; index < ROW_SIZE; index++) counts[index]; {

    Read the article

  • How to connect these together?

    - by Biertago
    I've got a mysql database created by phpMyAdmin and I want to use it in my Qt project. I tried it on Visual Studio 2010 with an qt addon but it didn't work neither. In Qt Creator, I add: QT += sql in a .pro file and include: #include <QSqlDatabase> in the main file but there's a driver error. I don't know even where to start and each google page shows something different. I tried to look for some guide but there is nothing which concerns everything in []s.

    Read the article

  • cygwin c sem_init

    - by RileyVanZeeland
    if((sem_init(sem, 1, 1)) == 1) perror("error initiating sem"); If I include this line of code my program simply starts and exits. I just started learning how to use semaphores. I'm using cygwin and when this line is commented out the printf's ABOVE this print to console but when include this, nothing happens. I did the following to get cygserver going- CYGWIN=server ran /bin/cygserver-config ran /usr/sbin/cygserver for the config it said the cygserver is already running And for the sygserver it saids- initailaizing complete failed to created named pipe: is the daemon already running? fatal error on IPC transport: closing down Any ideas?

    Read the article

  • Redundant naming in C/C++ typedefs/structs

    - by bloomy
    #include <stdio.h> #include <string.h> const int NAMELEN=30; const int MAXCLASSSIZE=10; typedef struct StudentRec { char lastname[NAMELEN]; char firstname[NAMELEN]; long int ID; int finalmark; }Student; I'm new to coding..and I have a question about why there is Student; after the bracket.. is it a format that we have to follow.

    Read the article

  • Can func get the lineno who call itself? (C/C++)

    - by kingkai
    Hi, I've a problem , as the following code discribe itself. 1 #include<stdlib.h> 2 #include<stdio.h> 3 void log() 4 { 5 printf("Log [Line:%d]\n",__LINE__); 6 } 7 int main() 8 { 9 log(); 10 log(); 11 } The expected result is Log [Line:9] Log [Line:10] But, the fact is Log [Line:5] Log [Line:5] No surprising, LINE has been substituted at the pre-process stage as 5. My Question is, how to design the log function to get the expected result? Thanks!

    Read the article

  • Multiple inclusion of header file c++

    - by iSight
    Hi, I have a problem regarding multiple inclusion of header file in C++ code. say for example, i have three class X,Y,Z. X and Y are derived from Base class Z. And i want to create an instance of X in Y. The code will go like this. class Z{some code} class X:public Z{some code};//here #include header of class Z added class Y:public Z //here #include header of class Z added as well as of X class {private: X* mX;//instance of X some code}; So in this multiple definition of all methods of base class arises. how can i cope with this problem

    Read the article

  • regex no character

    - by iamnotmad
    In this text: warning here there are several types of warnings in this string warning.gif at the end warning end of line warning I want to match every warning except warning.gif. I cannot seem to get it to include the last one that has no character (control or otherwise) after it. using warnings?[^\.] gets what I want except for the last warning (on the last line). I think because there is no character at all after. How can I get it to include that one?

    Read the article

  • Add list type to association

    - by teucer
    Hi All, I am using the eUML2 (Free version) plugin to draw a UML class diagram. Now, let's assume I have a class Person and a class Car. I want the class Person to have a member cars which is a List<Car>, i.e. private List<Car> cars = null. My question is how do I include this information in the class diagram? To be more precise, how do I include the type information for the List in the eUML2 association? Regards

    Read the article

< Previous Page | 138 139 140 141 142 143 144 145 146 147 148 149  | Next Page >