# slartg.f man page

slartg.f —

## Synopsis

### Functions/Subroutines

subroutine **slartg** (F, G, CS, SN, R)**SLARTG** generates a plane rotation with real cosine and real sine.

## Function/Subroutine Documentation

### subroutine slartg (realF, realG, realCS, realSN, realR)

**SLARTG** generates a plane rotation with real cosine and real sine.

**Purpose:**

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.

**Parameters:**-
*F*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.

**Date:**September 2012

Definition at line 98 of file slartg.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

slartg(3) is an alias of slartg.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK