test program of vector struct

sample_vector.c

#include <math.h>

typedef struct {
  double x;
  double y;
} vector;

vector make_vector(double x,double y);
vector plus_vector(vector a,vector b);
vector minus_vector(vector a,vector b);
double dot_product_vector(vector a,vector b);
double abs_vector(vector a);
vector scalar_multiple_vector(double a,vector b);

vector make_vector(double x,double y)
{
  vector ret;

  ret.x = x;
  ret.y = y;

  return ret;
}

vector plus_vector(vector a,vector b)
{
  vector ret;

  ret.x = a.x + b.x;
  ret.y = a.y + b.y;

  return ret;
}

vector minus_vector(vector a,vector b)
{
  vector ret;

  ret.x = a.x - b.x;
  ret.y = a.y - b.y;

  return ret;
}

double dot_product_vector(vector a,vector b)
{
  double ret;

  ret = a.x * b.x + a.y * b.y;

  return ret;
}

double abs_vector(vector a)
{
  double ret;

  ret = sqrt(a.x * a.x + a.y * a.y);

  return ret;
}

vector scalar_multiple_vector(double a,vector b)
{
  b.x *= a;
  b.y *= a;

  return b;
}

test_vector.c

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

typedef struct {
  double x;
  double y;
} vector;

extern vector make_vector(double x,double y);
extern vector plus_vector(vector a,vector b);
extern vector minus_vector(vector a,vector b);
extern double dot_product_vector(vector a,vector b);
extern double abs_vector(vector a);
extern vector scalar_multiple_vector(double a,vector b);

int main(void)
{
  srand((unsigned int) time(NULL));

  int t;
  //start test of plus
  for (t = 0;t < 100;t++)
    {
      double tmp[4] = { rand() / rand(),rand() / rand(),rand() / rand(),rand() / rand() };
      complex c_a = tmp[0] + tmp[1] * I;
      complex c_b = tmp[2] + tmp[3] * I;
      vector v_a = make_vector( tmp[0] , tmp[1]);
      vector v_b = make_vector( tmp[2] , tmp[3]);
      complex c_c = c_a + c_b;
      vector v_c = plus_vector(v_a,v_b);
      if ( creal(c_c) != v_c.x || cimag(c_c) != v_c.y )
	{
	  fprintf(stderr,"test of plus does not passed!!\n");
	  exit(1);
	}
    }
  fprintf(stderr,"test of plus passed!!\n");
  
  //start test of minus
  for (t = 0;t < 100;t++)
    {
      double tmp[4] = { rand() / rand(),rand() / rand(),rand() / rand(),rand() / rand() };
      complex c_a = tmp[0] + tmp[1] * I;
      complex c_b = tmp[2] + tmp[3] * I;
      vector v_a = make_vector( tmp[0] , tmp[1]);
      vector v_b = make_vector( tmp[2] , tmp[3]);
      complex c_c = c_a - c_b;
      vector v_c = minus_vector(v_a,v_b);
      if ( creal(c_c) != v_c.x || cimag(c_c) != v_c.y )
	{
	  fprintf(stderr,"test of minus does not passed!!\n");
	  exit(1);
	}
    }
  fprintf(stderr,"test of minus passed!!\n");
  
  //start test of dot product
  for (t = 0;t < 100;t++)
    {
      double tmp[4] = { rand() / rand(),rand() / rand(),rand() / rand(),rand() / rand() };
      complex c_a = tmp[0] + tmp[1] * I;
      complex c_b = tmp[2] + tmp[3] * I;
      vector v_a = make_vector( tmp[0] , tmp[1]);
      vector v_b = make_vector( tmp[2] , tmp[3]);
      double v_dot = dot_product_vector(v_a,v_b);
      if ( creal(c_a) * creal(c_b) + cimag(c_a) * cimag(c_b) != v_dot )
	{
	  fprintf(stderr,"test of dot product does not passed!!\n");
	  exit(1);
	}
    }
  fprintf(stderr,"test of dot product passed!!\n");

  //start test of abs
  for (t = 0;t < 100;t++)
    {
      double tmp[4] = { rand() / rand(),rand() / rand(),rand() / rand(),rand() / rand() };
      complex c_a = tmp[0] + tmp[1] * I;
      vector v_a = make_vector( tmp[0] , tmp[1]);
      double v_abs = abs_vector(v_a);
      if ( cabs(c_a) != v_abs )
	{
	  fprintf(stderr,"test of abs does not passed!!\n");
	  exit(1);
	}
    }
  fprintf(stderr,"test of abs passed!!\n");

  //start test of scalar multiple
  for (t = 0;t < 100;t++)
    {
      double tmp[4] = { rand() / rand(),rand() / rand(),rand() / rand(),rand() / rand() };
      complex c_a = tmp[0] + tmp[1] * I;
      vector v_a = make_vector( tmp[0] , tmp[1]);
      vector v_scala = scalar_multiple_vector(tmp[2],v_a);
      if ( creal(c_a) * tmp[2] != v_scala.x || cimag(c_a) * tmp[2] != v_scala.y )
	{
	  fprintf(stderr,"test of scalar multiple does not passed!!\n");
	  exit(1);
	}
    }
  fprintf(stderr,"test of scalar multiple passed!!\n");

  fprintf(stderr,"all tests passed!!\n");

  return 0;
}