slartg (l) - Linux Man Pages
slartg: generate a plane rotation so that [ CS SN ]
NAMESLARTG - generate a plane rotation so that [ CS SN ]
- SUBROUTINE SLARTG(
- F, G, CS, SN, R )
- REAL CS, F, G, R, SN
PURPOSESLARTG generate a plane rotation so that
This is a slower, more accurate version of the BLAS1 routine SROTG, with the following other differences:
F and G are unchanged on return.
If G=0, then CS=1 and SN=0.
If F=0 and
floating point operations
there are zeros on the diagonal).
If F exceeds G in magnitude, CS will be positive.
- F (input) REAL
- The first component of vector to be rotated.
- G (input) REAL
- The second component of vector to be rotated.
- CS (output) REAL
- The cosine of the rotation.
- SN (output) REAL
- The sine of the rotation.
- R (output) REAL
The nonzero component of the rotated vector.
This version has a few statements commented out for thread safety
(machine parameters are computed on each entry). 10 feb 03, SJH.