slartg(l) [redhat man page]

SLARTG(l)								 )								 SLARTG(l)

NAME

       SLARTG - generate a plane rotation so that  [ CS SN ]

SYNOPSIS

       SUBROUTINE SLARTG( F, G, CS, SN, R )

	   REAL 	  CS, F, G, R, SN

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.

ARGUMENTS

       F       (input) REAL
	       The first component of vector to be rotated.

       G       (input) REAL
	       The second component of vector to be rotated.

       CS      (output) REAL
	       The cosine of the rotation.

       SN      (output) REAL
	       The sine of the rotation.

       R       (output) REAL
	       The nonzero component of the rotated vector.

LAPACK version 3.0						   15 June 2000 							 SLARTG(l)

slartg.f(3)							      LAPACK							       slartg.f(3)

NAME

       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.

Version 3.4.2							  Tue Sep 25 2012						       slartg.f(3)