# slartgp.f - Man Page

## Synopsis

### Functions/Subroutines

subroutine **slartgp** (F, G, CS, SN, R)**SLARTGP** generates a plane rotation so that the diagonal is nonnegative.

## Function/Subroutine Documentation

### subroutine slartgp (real F, real G, real CS, real SN, real R)

**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.

**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:**December 2016

Definition at line 97 of file slartgp.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page slartgp(3) is an alias of slartgp.f(3).

Tue Nov 14 2017 Version 3.8.0 LAPACK