Computes the parameters for a Givens rotation.
Syntax
void cblas_srotg (float *a, float *b, float *c, float *s);
void cblas_drotg (double *a, double *b, double *c, double *s);
void cblas_crotg (void *a, const void *b, float *c, void *s);
void cblas_zrotg (void *a, const void *b, double *c, void *s);
Include Files
- mkl.h
Description
Given the Cartesian coordinates (a, b) of a point, these routines return the parameters c, s, r, and z associated with the Givens rotation. The parameters c and s define a unitary matrix such that:
The parameter z is defined such that if |a| > |b|, z is s; otherwise if c is not 0 z is 1/c; otherwise z is 1.
Input Parameters
- a
Provides the x-coordinate of the point p.
- b
Provides the y-coordinate of the point p.
Output Parameters
- a
Contains the parameter r associated with the Givens rotation.
- b
Contains the parameter z associated with the Givens rotation.
- c
Contains the parameter c associated with the Givens rotation.
- s
Contains the parameter s associated with the Givens rotation.