Function to convert a Cartesian co-ordinate to polar form. More...

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

Include dependency graph for cartesian_to_polar.c:

Macros
#define	_USE_MATH_DEFINES
	required for MS Visual C

Functions
void	to_polar (double x, double y, double r, double theta)
	Function to convert cartesian coordinates to polar.

double	get_rand (double lim1, double lim2)
	Generate a random number in the given limits.

void	test ()
	Test implementation.

int	main ()
	Main function.

Detailed Description

Function to convert a Cartesian co-ordinate to polar form.

Function Documentation

◆ get_rand()

double get_rand	(	double	lim1,
		double	lim2
	)

Generate a random number in the given limits.

Parameters

lim1	lower limit
lim2	upper limit

Returns: random number in the given range

{
    double r = (double)rand() / RAND_MAX;  // value in [0,1)
    return (lim2 - lim1) * r + lim1;       // scale to range
}

◆ main()

int main ( void )

Main function.

{
    test();
 
    return 0;
}

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◆ test()

void test ( void )

Test implementation.

{
    srand(10);
    int NUM_TESTS = 5;
 
    for (int i = 0; i < NUM_TESTS; i++)
    {
        double r, theta;
        printf("Test %d.... ", i);
        double x = get_rand(-5, 5);
        double y = get_rand(-5, 5);
        printf("(%.2g, %.2g).... ", x, y);
        to_polar(x, y, &r, &theta);
        assert(fabs(r - hypot(x, y)) < 0.01);
        assert(fabs(theta - atan2(y, x)) < 0.01);
        printf("passed\n");
    }
}

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◆ to_polar()

void to_polar	(	double	x,
		double	y,
		double *	r,
		double *	theta
	)

Function to convert cartesian coordinates to polar.

\begin{eqnarray*} r &=& \sqrt{x^2+y^2}\\ \theta &=& \atan\frac{y}{x} \end{eqnarray*}