C Library Functions  - srotm (3)

NAME

srotm(3f) - [BLAS:SINGLE_BLAS_LEVEL1] Apply a modified Given’s rotation.

CONTENTS

Synopsis
Definition
Options
     Sx
     Sy
Authors
See Also

SYNOPSIS

subroutine srotm(n,sx,incx,sy,incy,sparam)

      .. Scalar Arguments ..
      integer,intent(in) :: incx,incy,n
      ..
      .. Array Arguments ..
      real,intent(in)    :: sparam(5)
      real,intent(inout) :: sx(*),sy(*)
      ..

DEFINITION

APPLY THE MODIFIED GIVENS TRANSFORMATION, H, TO THE 2 BY N MATRIX

(SX**T) , WHERE **T INDICATES TRANSPOSE. THE ELEMENTS OF SX ARE IN (SX**T)

SX(LX+I*INCX), I = 0 TO N-1, WHERE LX = 1 IF INCX .GE. 0, ELSE LX = (-INCX)*N, AND SIMILARLY FOR SY USING USING LY AND INCY. WITH SPARAM(1)=SFLAG, H HAS ONE OF THE FOLLOWING FORMS..

       SFLAG=-1.E0     SFLAG=0.E0        SFLAG=1.E0     SFLAG=-2.E0

(SH11 SH12) (1.E0 SH12) (SH11 1.E0) (1.E0 0.E0) H=( ) ( ) ( ) ( ) (SH21 SH22), (SH21 1.E0), (-1.E0 SH22), (0.E0 1.E0).

SEE SROTMG FOR A DESCRIPTION OF DATA STORAGE IN SPARAM.

OPTIONS

    N

N is INTEGER number of elements in input vector(s)

    SX

SX is REAL array, dimension ( 1 + ( N - 1 )*abs( INCX ) )

    INCX

INCX is INTEGER storage spacing between elements of SX

    SY

SY is REAL array, dimension ( 1 + ( N - 1 )*abs( INCY ) )

    INCY

INCY is INTEGER storage spacing between elements of SY

    SPARAM

SPARAM is REAL array, dimension (5) SPARAM(1)=SFLAG SPARAM(2)=SH11 SPARAM(3)=SH21 SPARAM(4)=SH12 SPARAM(5)=SH22

AUTHORS

o Univ. of Tennessee
o Univ. of California Berkeley
o Univ. of Colorado Denver
o NAG Ltd.

 date:November 2017

SEE ALSO

Online html documentation available at http://www.netlib.org/lapack/explore-html/


Nemo Release 3.1 srotm (3) July 22, 2023
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