DragonFly On-Line Manual Pages

Search: Section:  

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                   Sat Nov 16 2013                    slartg.f(3)

Search: Section: