Thread: Complex Number Implementation

Here is my code for a program that adds and multiplies two complex numbers:

main.c

Code:

#include <stdio.h>
#include "complex.h"
 
int main ( int argc , char *argv[] ) {
 
  comp *ptr1, *ptr2, *j, *k, *sum, *product;
  double r, i;
 
  printf ( "Enter first complex number-\n" );
  printf ( "Enter real part: " );
  scanf  ( "%d",  &r );
  printf ( "Enter imaginary part: " );
  scanf  ( "%d",  &i );
 
  load_complex ( ptr1, r, i );
   
  printf ( "Enter second complex number-\n" );
  printf ( "Enter real part: " );
  scanf  ( "%d",  &r );
  printf ( "Enter imaginary part: " );
  scanf  ( "%d",  &i );
 
  load_complex ( ptr2, r, i );
 
  add_complex  ( sum, ptr1, ptr2 );
  retrieve_complex ( sum, j, k );
 
  printf ( "Sum is %lf%lf\n", sum->real, sum->imaginary );
   
  multiply_complex ( product, ptr1, ptr2 );
  retrieve_complex ( product, j, k );
 
  printf ( "Product is %lf%lf\n", product->real, product->imaginary );
 
  return ( 0 );
 
}

complex.h and complex.c:

Code:

/*
  complex.h
*/
 
typedef struct {
  double real;
  double imaginary;
} comp;
 
extern void load_complex ( comp *p_complex, double real,
					double imaginary );
 
extern void retrieve_complex ( comp *p_complex, double *p_real,
						double *imaginary );
 
extern void add_complex ( comp *p_sum, comp *p_complex1,
				   comp *p_complex2 );
 
extern void multiply_complex ( comp *p_product, comp *p_complex1,
						comp *p_complex2 );
}

/*
  complex.c
*/
 
#include "complex.h"
 
extern void load_complex ( comp *p_complex, double real, double imaginary ) {
 
  p_complex->real = real;
  p_complex->imaginary = imaginary;
 
}
 
extern void retrieve_complex ( comp *p_complex, double *p_real,
						double *p_imaginary ) {
 
  *p_real = p_complex->real;
  *p_imaginary = p_complex->imaginary;
 
}
 
extern void add_complex ( comp *p_sum, comp *p_complex1, comp *p_complex2 ) {
 
  p_sum->real = p_complex1->real + p_complex2->real;
 
  p_sum->imaginary = p_complex1->imaginary + p_complex2->imaginary;
 
}
 
extern void multiply_complex ( comp *p_product, comp *p_complex1,
						comp *p_complex2 ) {
 
  p_product->real = p_complex1->real * p_complex2->real -
	p_complex1->imaginary * p_complex2->imaginary;
 
  p_product->imaginary = p_complex1->real * p_complex2->imaginary *
	p_complex1->imaginary * p_complex2->real;
 
}

I'm receiving seg faults at the load_complex function ( gdb ), but I don't know what's wrong with the function. Originally, I was able to enter two complex numbers and then it seg faulted at retrieve, but for some reason now it's seg'n at the load's.. any ideas?

Originally Posted by Sebastiani

well, since a pointer is just a variable that contains an address - the object at that address has to exist for the pointer to be valid!

d'oh.. thank you.

Cheers