t8_vec.h File Reference

We define routines to handle 3-dimensional vectors. More...

#include <t8.h>

Go to the source code of this file.

Functions
double	t8_vec_norm (const double vec[3])
	Vector norm. More...
double	t8_vec_dist (const double vec_x[3], const double vec_y[3])
	Euclidean distance of X and Y. More...
void	t8_vec_ax (double vec_x[3], const double alpha)
	Compute X = alpha * X. More...
void	t8_vec_axy (const double vec_x[3], double vec_y[3], const double alpha)
	Compute Y = alpha * X. More...
void	t8_vec_axb (const double vec_x[3], double vec_y[3], const double alpha, const double b)
	Y = alpha * X + b. More...
void	t8_vec_axpy (const double vec_x[3], double vec_y[3], const double alpha)
	Y = Y + alpha * X. More...
void	t8_vec_axpyz (const double vec_x[3], const double vec_y[3], double vec_z[3], const double alpha)
	Z = Y + alpha * X. More...
double	t8_vec_dot (const double vec_x[3], const double vec_y[3])
	Dot product of X and Y. More...
void	t8_vec_cross (const double vec_x[3], const double vec_y[3], double cross[3])
	Cross product of X and Y. More...

Detailed Description

We define routines to handle 3-dimensional vectors.

Function Documentation

t8_vec_ax()

void t8_vec_ax	(	double	vec_x[3],
		const double	alpha
	)

Compute X = alpha * X.

Parameters

[in,out]	vec_x	A 3D vector. On output set to alpha * vec_x.
[in]	alpha	A factor.

t8_vec_axb()

void t8_vec_axb	(	const double	vec_x[3],
		double	vec_y[3],
		const double	alpha,
		const double	b
	)

Y = alpha * X + b.

Parameters

[in]	vec_x	A 3D vector.
[out]	vec_y	On input, a 3D vector. On output set to alpha * vec_x + b.
[in]	alpha	A factor.
[in]	b	An offset.

Note

It is possible that vec_x = vec_y on input to overwrite x

t8_vec_axpy()

void t8_vec_axpy	(	const double	vec_x[3],
		double	vec_y[3],
		const double	alpha
	)

Y = Y + alpha * X.

Parameters

[in]	vec_x	A 3D vector.
[in,out]	vec_y	On input, a 3D vector. On output set to vec_y + alpha * vec_x
[in]	alpha	A factor.

t8_vec_axpyz()

void t8_vec_axpyz	(	const double	vec_x[3],
		const double	vec_y[3],
		double	vec_z[3],
		const double	alpha
	)

Z = Y + alpha * X.

Parameters

[in]	vec_x	A 3D vector.
[in]	vec_y	A 3D vector.
[out]	vec_z	On output set to vec_y + alpha * vec_x

t8_vec_axy()

void t8_vec_axy	(	const double	vec_x[3],
		double	vec_y[3],
		const double	alpha
	)

Compute Y = alpha * X.

Parameters

[in]	vec_x	A 3D vector.
[out]	vec_z	On output set to alpha * vec_x.
[in]	alpha	A factor.

t8_vec_cross()

void t8_vec_cross	(	const double	vec_x[3],
		const double	vec_y[3],
		double	cross[3]
	)

Cross product of X and Y.

Parameters

[in]	vec_x	A 3D vector.
[in]	vec_y	A 3D vector.
[out]	cross	On output, the cross product of vec_x and vec_y.

t8_vec_dist()

double t8_vec_dist	(	const double	vec_x[3],
		const double	vec_y[3]
	)

Euclidean distance of X and Y.

Parameters

[in]	vec_x	A 3D vector.
[in]	vec_y	A 3D vector.

Returns

The euclidean distance. Equivalent to norm (X-Y).

t8_vec_dot()

double t8_vec_dot	(	const double	vec_x[3],
		const double	vec_y[3]
	)

Dot product of X and Y.

Parameters

[in]	vec_x	A 3D vector.
[in]	vec_y	A 3D vector.

Returns

The dot product vec_x * vec_y

t8_vec_norm()

double t8_vec_norm

(

const double

vec[3]

)

Vector norm.

Parameters

[in]

vec

A 3D vector.

Returns

The norm of vec.