NAME

BLAS/SRC/srotm.f

SYNOPSIS

Functions/Subroutines

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

Function/Subroutine Documentation

subroutine srotm (integer n, real, dimension() sx, integer incx, real, dimension() sy, integer incy, real, dimension(5) sparam)

SROTM

Purpose:



    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.

Parameters



          N is INTEGER


         number of elements in input vector(s)



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

INCX



          INCX is INTEGER


         storage spacing between elements of SX



          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

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 96 of file srotm.f.

Author