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CentOS 7.0 - man page for dlartgs (centos section 3)

dlartgs.f(3)							      LAPACK							      dlartgs.f(3)

NAME
dlartgs.f -
SYNOPSIS
Functions/Subroutines subroutine dlartgs (X, Y, SIGMA, CS, SN) DLARTGS generates a plane rotation designed to introduce a bulge in implicit QR iteration for the bidiagonal SVD problem. Function/Subroutine Documentation subroutine dlartgs (double precisionX, double precisionY, double precisionSIGMA, double precisionCS, double precisionSN) DLARTGS generates a plane rotation designed to introduce a bulge in implicit QR iteration for the bidiagonal SVD problem. Purpose: DLARTGS generates a plane rotation designed to introduce a bulge in Golub-Reinsch-style implicit QR iteration for the bidiagonal SVD problem. X and Y are the top-row entries, and SIGMA is the shift. The computed CS and SN define a plane rotation satisfying [ CS SN ] . [ X^2 - SIGMA ] = [ R ], [ -SN CS ] [ X * Y ] [ 0 ] with R nonnegative. If X^2 - SIGMA and X * Y are 0, then the rotation is by PI/2. Parameters: X X is DOUBLE PRECISION The (1,1) entry of an upper bidiagonal matrix. Y Y is DOUBLE PRECISION The (1,2) entry of an upper bidiagonal matrix. SIGMA SIGMA is DOUBLE PRECISION The shift. CS CS is DOUBLE PRECISION The cosine of the rotation. SN SN is DOUBLE PRECISION The sine of the rotation. Author: Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Date: September 2012 Definition at line 91 of file dlartgs.f. Author Generated automatically by Doxygen for LAPACK from the source code. Version 3.4.2 Tue Sep 25 2012 dlartgs.f(3)