Can't use pow() and sin()....

[Victo]

I tried to use pow() and sin().

but even I included <math.h>,
I can't use the 2 functions....

Why's that????

for example,


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

int main(void)
{
double a=2;
printf("%lf\n",sin(2));
return 1;
}


it returns the below error

Undefined first referenced
symbol in file
sin /var/tmp//ccJ0ckFm.o
ld: fatal: Symbol referencing errors. No output written to a.out
collect2: ld returned 1 exit status


Why's that???

 

[Eric Sosman]

I tried to use pow() and sin().

but even I included <math.h>,
I can't use the 2 functions....

Why's that????

This is Question 14.3 in the comp.lang.c Frequently
Asked Questions (FAQ) list

http://www.eskimo.com/~scs/C-faq/top.html

 

[Ravi Uday]

I tried to use pow() and sin().

but even I included <math.h>,
I can't use the 2 functions....

Why's that????

for example,


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

int main(void)
{
double a=2;
printf("%lf\n",sin(2));
return 1;
}


it returns the below error

Undefined first referenced
symbol in file
sin /var/tmp//ccJ0ckFm.o
ld: fatal: Symbol referencing errors. No output written to a.out
collect2: ld returned 1 exit status


Why's that???

How are you compiling your file(s) ?

Have you seen FAQ: 14.3 ?

http://www.eskimo.com/~scs/C-faq/top.html

- Ravi

 

[Steffen Jakob]

I tried to use pow() and sin().

but even I included <math.h>,
I can't use the 2 functions....

Why's that????

Link with -lm

Greetings,
Steffen.

 

[ranveerkunal]

gcc foo.c -o foo.o -lm

 

[jacob navia]

I tried to use pow() and sin().

but even I included <math.h>,
I can't use the 2 functions....

Why's that????

for example,


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

int main(void)
{
double a=2;
printf("%lf\n",sin(2));
return 1;
}


it returns the below error

Undefined first referenced
symbol in file
sin /var/tmp//ccJ0ckFm.o
ld: fatal: Symbol referencing errors. No output written to a.out
collect2: ld returned 1 exit status


Why's that???

Open Letter to the gcc team:

Dear Sirs:

Regularly in comp.lang.c we get questions like

Can't use pow() and sin()

Could you INCLUDE the math library BY DEFAULT?????

Most compilers in the world spare their users this. The
math library will be included, sometimes together with
other libraries.

Rationale:

The standard language specifies sin/cos/pow etc. Since
those functions are part of the *standard* there is NO
reason to separate them from the C library. The distinction
is completely artificial.

Users do not have to include the C library. Why should
they include the math library?

Yours sincerely

 

[Mark McIntyre]

Most compilers in the world spare their users this. The
math library will be included, sometimes together with
other libraries.

I'm mostly with you on this, there's no reason (any longer) to have
the math component of the standard library unincluded by default,
but...

Rationale:

The standard language specifies sin/cos/pow etc. Since
those functions are part of the *standard* there is NO
reason to separate them from the C library.

.... remember that the Standard Library is NOT part of the gcc
compiler.

The distinction is completely artificial.

agreed. However I believe the gcc guys chose to implement a compiler,
and leave the standard library to the experts.