CODEWITHSUNDEEP
windowsmathvisual-c++
Kumar
Kumar

Reputation: 11

complex and double complex methods not working in visual studio c project

The below code is throwing error in Visual Studio C project. That same code is working in Linux with GCC compiler. Please let me know any solution to execute properly in Windows.

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

typedef struct { 
    float r, i;
} complex_;


double c_abs(complex_* z)
{
    return  (cabs(z->r + I * z->i));
}

int main()
{
    complex_ number1 = { 3.0, 4.0 };

    double d = c_abs(&number1);

    printf("The absolute value of %f + %fi is %f\n", number1.r, number1.i, d);    
    return 0;
}

The error I am getting was

C2088: '*': illegal for struct

Here what t I observed the I macro not working properly... So is there any other way we can handle in Windows?

Upvotes: 1

Views: 986

Answers (1)

dxiv
dxiv

Reputation: 17678

error C2088: '*': illegal for struct

This is the error MSVC returns when compiling the code (as C) for this line.

  return  (cabs(z->r + I * z->i));

The MSVC C compiler does not have a native complex type, and (quoting the docs) "therefore the Microsoft implementation uses structure types to represent complex numbers".

The imaginary unit I a.k.a. _Complex_I is defined as an _Fcomplex structure in <complex.h>, which explains compile error C2088, since there is no operator * to multiply that structure with a float value.

Even if the multiplication worked out by some magic, the end result would be a float value being passed into the cabs call, but MSVC declares cabs as double cabs(_Dcomplex z); and there is no automatic conversion from float to _Dcomplex so the call would still fail to compile.

What would work with MSVC, however, is replace that line with the following, which constructs a _Dcomplex on the fly from the float real and imaginary parts.

  return  cabs(_Dcomplex{z->r, z->i});

Upvotes: 1

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