em_edificacao/vector.c at main · pudiva/em_edificacao · GitHub

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#include <math.h>
#include "vector.h"

const double v_zero[2] = {0, 0};

void v_copy(const double* x, double* y)
{
	y[0] = x[0];
	y[1] = x[1];
}

void v_axpy(double a, const double* x, double* y)
{
	y[0] = a * x[0] + y[0];
	y[1] = a * x[1] + y[1];
}

void v_scal(double a, double* x)
{
	x[0] *= a;
	x[1] *= a;
}

void v_mul(const double* x, double* y)
{
	y[0] *= x[0];
	y[1] *= x[1];
}

void v_div(const double* x, double* y)
{
	y[0] /= x[0];
	y[1] /= x[1];
}

double v_dot(const double* x, const double* y)
{
	return (x[0] * y[0] + x[1] * y[1]);
}

double v_nrm2(const double* x)
{
	return sqrt(v_dot(x, x));
}

double v_normalize(double* x)
{
	double l;

	l = v_nrm2(x);
	l = EPSILON < l ? l : 0;
	v_scal((0 < l ? 1.0/l : 0), x);
	return l;
}