Complex number calculation using library

[Reshmi]

Hi,

I have this C code which does complex number arithmetic. When I try to
write a similar file for C++, it says that "creal’ was not declared in
this scope". Can anyone give a better idea to write it using
"complex.h", other than using own data structures?

#include <stdio.h>
#include <complex.h>

int main(){

// double pi = 4*atan2(1);

double complex A = 32 + 24*I;
double complex B = 64 + 48*I;
double complex sum = A + B;

printf("\na is %f + %fi\n",creal(A), cimag(A));
printf("b is %f + %fi\n",creal(B), cimag(B));
printf("sum is %f + %fi\n",creal(sum), cimag(sum));
printf("sum: abs = %f , angle = %f\n", cabs(sum), carg(sum));

return(0);

}


Thanks,
Reshmi

 

[Ian Collins]

Hi,

I have this C code which does complex number arithmetic. When I try to
write a similar file for C++, it says that "creal’ was not declared in
this scope". Can anyone give a better idea to write it using
"complex.h", other than using own data structures?

#include <stdio.h>
#include <complex.h>

C++ does not include C99's _Complex type.

Use std::complex from <complex>

 

[Kai-Uwe Bux]

Hi,

I have this C code which does complex number arithmetic. When I try to
write a similar file for C++, it says that "creal? was not declared in
this scope". Can anyone give a better idea to write it using
"complex.h", other than using own data structures?

#include <stdio.h>
#include <complex.h>

int main(){

// double pi = 4*atan2(1);

double complex A = 32 + 24*I;
double complex B = 64 + 48*I;
double complex sum = A + B;

printf("\na is %f + %fi\n",creal(A), cimag(A));
printf("b is %f + %fi\n",creal(B), cimag(B));
printf("sum is %f + %fi\n",creal(sum), cimag(sum));
printf("sum: abs = %f , angle = %f\n", cabs(sum), carg(sum));

return(0);

}

#include <complex>
#include <iostream>

typedef std::complex< double > double_complex;

int main ( void ) {
double_complex A ( 32, 24 );
double_complex B ( 64, 48 );
double_complex sum = A + B;
std::cout << "A is " << A << '\n';
std::cout << "B is " << B << '\n';
std::cout << "sum is " << sum << '\n';
std::cout << "sum: abs = " << std::abs( sum )
<< ", angle = " << std::arg( sum ) << '\n';
}


Best

Kai-Uwe Bux

 

[James Kanze]

C++ does not include C99's _Complex type.

Use std::complex from <complex>

Or, given his code, compile the program as C (and ask any
further questions about it in comp.lang.c, of course).

 

[Reshmi]

Hi James,

This is part of a bigger function. All other files are in C++. So, I
wanted to write this function in C++ as well.

Reshmi