How to link the libm library in microsoft visual studio 2010

Question

please, could you help me how we link the libm math library in microsoft visual studio 2010,

in order to use some trigonometric function in a c program ?

Create a project in Visual Studio 2010 usually loads those for you. What is the actual error message you see? — Just a HK developer, Sep 17 '14 at 01:17
What have you done so far? add the .lib files with the other MSVC 2010 libraries under C:/..../VC/include folder. Then if there are DLL files, add the .dll files under C:/Windows.../System32. To link, with MSVC 2010 go to Properties->Linker->Input->Additional Dependencies then add libm.lib files. — Juniar, Sep 17 '14 at 03:45

score 1 · Accepted Answer · answered Sep 17 '14 at 02:06

It should only be necessary to put

#include <math.h>

in your program.

The following compiles without error or warning, in a new empty project in VS2010:

#include <stdio.h>
#include <math.h>

int main(){
  double a,b,c;
  char d;
  a = 0.0;
  b = cos(a);
  c = sqrt(b);
  printf("cos(%lf) = %lf, sqrt(cos(%lf)) = %lf\n", a, b, a, c);
  d = getchar();
  return 0;
}

Here is the VS2010 compile output:

1>------ Rebuild All started: Project: test3, Configuration: Debug Win32 ------
1>  source.c
1>  test3.vcxproj -> c:\users\andy\documents\visual studio 2010\Projects\test3\Debug\test3.exe
========== Rebuild All: 1 succeeded, 0 failed, 0 skipped ==========

If I omit #include <math.h> I get this:

1>------ Rebuild All started: Project: test3, Configuration: Debug Win32 ------
1>  source.c
1>c:\users\andy\documents\visual studio 2010\projects\test3\test3\source.c(9): warning C4013: 'cos' undefined; assuming extern returning int
1>c:\users\andy\documents\visual studio 2010\projects\test3\test3\source.c(10): warning C4013: 'sqrt' undefined; assuming extern returning int
1>  test3.vcxproj -> c:\users\andy\documents\visual studio 2010\Projects\test3\Debug\test3.exe
========== Rebuild All: 1 succeeded, 0 failed, 0 skipped ==========

No changes need to be made to the VS2010 libraries that are linked.

There are no red underlines (intellisense errors) either.

your program work perfectly, but in my case the cos function is in another function (function_name.c ), and cos function still underlined in red — user3466199, Sep 17 '14 at 11:07
You need to put `#include ` at the top of any file where you are using `cos`. So put it in your `function_name.c` file also. — lone gold, Sep 17 '14 at 21:08
yeah that correct, the problem has been resolved, thanks very much — user3466199, Sep 18 '14 at 19:18

score 0 · Answer 2 · answered Sep 17 '14 at 01:36

0

I think I know your problem. It is not the linker problem.

It is the header file name. For example, to use math library, you type #include <math.h>. If you type #include <math>, you will get cannot include file error.

Create a Visual C++ project in Visual Studio 2010 as per usual. Use the following to test:

#include <math.h>
#include <iostream>
using namespace std;

int main(void)
{
    double test = 9.0;
    double result = sqrt(test);

    cout << "test = " << test << "   result = " << result << endl;
}

And the result is:

test = 9   result = 3

Hope this helps.

answered Sep 17 '14 at 01:36

Just a HK developer

680
12
29

unfortunently not in my case, there is a red line under sqrt function ? – user3466199 Sep 17 '14 at 01:39
1

I want a program in c not c++ – user3466199 Sep 17 '14 at 01:39
To compile C program go to Properties->C/C++->Advanced-> then select Compile as C Code(/TP). – Juniar Sep 17 '14 at 03:53
Ah. If there is a red line under sqrt function, please just say that in the first place! If there is a red line, that means the {[spell checker](http://msdn.microsoft.com/en-us/library/jj170375.aspx)} is working! Then just make sure you have the `#include ` at the top of the file. – Just a HK developer Sep 17 '14 at 07:04

How to link the libm library in microsoft visual studio 2010

2 Answers2