.TH "slartgs.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME slartgs.f \- .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBslartgs\fP (X, Y, SIGMA, CS, SN)" .br .RI "\fI\fBSLARTGS\fP generates a plane rotation designed to introduce a bulge in implicit QR iteration for the bidiagonal SVD problem\&. \fP" .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine slartgs (realX, realY, realSIGMA, realCS, realSN)" .PP \fBSLARTGS\fP generates a plane rotation designed to introduce a bulge in implicit QR iteration for the bidiagonal SVD problem\&. .PP \fBPurpose: \fP .RS 4 .PP .nf SLARTGS 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. .fi .PP .RE .PP \fBParameters:\fP .RS 4 \fIX\fP .PP .nf X is REAL The (1,1) entry of an upper bidiagonal matrix. .fi .PP .br \fIY\fP .PP .nf Y is REAL The (1,2) entry of an upper bidiagonal matrix. .fi .PP .br \fISIGMA\fP .PP .nf SIGMA is REAL The shift. .fi .PP .br \fICS\fP .PP .nf CS is REAL The cosine of the rotation. .fi .PP .br \fISN\fP .PP .nf SN is REAL The sine of the rotation. .fi .PP .RE .PP \fBAuthor:\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP \fBDate:\fP .RS 4 September 2012 .RE .PP .PP Definition at line 91 of file slartgs\&.f\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.