clartg (l) - Linux Man Pages
clartg: generates a plane rotation so that [ CS SN ] [ F ] [ R ] [ __ ]
NAMECLARTG - generates a plane rotation so that [ CS SN ] [ F ] [ R ] [ __ ]
- SUBROUTINE CLARTG(
- F, G, CS, SN, R )
- REAL CS
- COMPLEX F, G, R, SN
PURPOSECLARTG generates a plane rotation so that
This is a faster version of the BLAS1 routine CROTG, except for the following differences:
F and G are unchanged on return.
If G=0, then CS=1 and SN=0.
If F=0, then CS=0 and SN is chosen so that R is real.
- F (input) COMPLEX
- The first component of vector to be rotated.
- G (input) COMPLEX
- The second component of vector to be rotated.
- CS (output) REAL
- The cosine of the rotation.
- SN (output) COMPLEX
- The sine of the rotation.
- R (output) COMPLEX
- The nonzero component of the rotated vector.
FURTHER DETAILS3-5-96 - Modified with a new algorithm by W. Kahan and J. Demmel This version has a few statements commented out for thread safety (machine parameters are computed on each entry). 10 feb 03, SJH.