gr_math.h File Reference

#include <gr_complex.h>

Include dependency graph for gr_math.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Functions
long	gr_gcd (long m, long n)
int	gr_isnan (double value)
int	gr_signbit (double x)
float	gr_fast_atan2f (float y, float x)
	Fast arc tangent using table lookup and linear interpolation.

---

Function Documentation

float gr_fast_atan2f	(	float	y,
		float	x
	)

Fast arc tangent using table lookup and linear interpolation.

Parameters:

	y	component of input vector
	x	component of input vector

Returns:

float angle angle of vector (x, y) in radians

This function calculates the angle of the vector (x,y) based on a table lookup and linear interpolation. The table uses a 256 point table covering -45 to +45 degrees and uses symetry to determine the final angle value in the range of -180 to 180 degrees. Note that this function uses the small angle approximation for values close to zero. This routine calculates the arc tangent with an average error of +/- 0.045 degrees.

long gr_gcd	(	long	m,
		long	n
	)

int gr_isnan

(

double

value

)

int gr_signbit

(

double

x

)

Referenced by atsci_sssr::update().