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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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subroutine slartg | ( | real | F, |
real | G, | ||
real | CS, | ||
real | SN, | ||
real | R | ||
) |
SLARTG generates a plane rotation with real cosine and real sine.
Download SLARTG + dependencies [TGZ] [ZIP] [TXT]
SLARTG generate a plane rotation so that [ CS SN ] . [ F ] = [ R ] where CS**2 + SN**2 = 1. [ -SN CS ] [ G ] [ 0 ] 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 (G .ne. 0), then CS=0 and SN=1 without doing any floating point operations (saves work in SBDSQR when there are zeros on the diagonal). If F exceeds G in magnitude, CS will be positive.
[in] | F | F is REAL The first component of vector to be rotated. |
[in] | G | G is REAL The second component of vector to be rotated. |
[out] | CS | CS is REAL The cosine of the rotation. |
[out] | SN | SN is REAL The sine of the rotation. |
[out] | R | R is 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. |
Definition at line 99 of file slartg.f.