gr_math.h File Reference

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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.

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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  )

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