lartgp - lartgp: generate plane rotation, more accurate than BLAS rot

Generated automatically by Doxygen for LAPACK from the source code. Version 3.12.0 Sun Jul 20 2025 01:40:05 lartgp(3)

subroutinedlartgp(doubleprecisionf,doubleprecisiong,doubleprecisioncs,doubleprecisionsn,doubleprecisionr)DLARTGP generates a plane rotation so that the diagonal is nonnegative. Purpose: DLARTGP generates 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 Level 1 BLAS routine DROTG, 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. The sign is chosen so that R >= 0. ParametersF F is DOUBLE PRECISION The first component of vector to be rotated. G G is DOUBLE PRECISION The second component of vector to be rotated. CS CS is DOUBLE PRECISION The cosine of the rotation. SN SN is DOUBLE PRECISION The sine of the rotation. R R is DOUBLE PRECISION 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. Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. subroutineslartgp(realf,realg,realcs,realsn,realr)SLARTGP generates a plane rotation so that the diagonal is nonnegative. Purpose: SLARTGP generates 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 Level 1 BLAS 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. The sign is chosen so that R >= 0. ParametersF F is REAL The first component of vector to be rotated. G G is REAL The second component of vector to be rotated. CS CS is REAL The cosine of the rotation. SN SN is REAL The sine of the rotation. 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. Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd.

lartgp - lartgp: generate plane rotation, more accurate than BLAS rot

Functions subroutine dlartgp (f, g, cs, sn, r) DLARTGP generates a plane rotation so that the diagonal is nonnegative. subroutine slartgp (f, g, cs, sn, r) SLARTGP generates a plane rotation so that the diagonal is nonnegative.