Developer Reference for Intel® oneAPI Math Kernel Library for C
?rotg
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
-
REAL for srotg DOUBLE PRECISION for drotg COMPLEX for crotg DOUBLE COMPLEX for zrotg Provides the x -coordinate of the point p .
- b
-
REAL for srotg DOUBLE PRECISION for drotg COMPLEX for crotg DOUBLE COMPLEX for zrotg 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
-
REAL for srotg DOUBLE PRECISION for drotg REAL for crotg DOUBLE PRECISION for zrotg Contains the parameter c associated with the Givens rotation.
- s
-
REAL for srotg DOUBLE PRECISION for drotg COMPLEX for crotg DOUBLE COMPLEX for zrotg Contains the parameter s associated with the Givens rotation.