LAPACK  3.5.0
LAPACK: Linear Algebra PACKage
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srotm.f File Reference

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Functions/Subroutines

subroutine srotm (N, SX, INCX, SY, INCY, SPARAM)
 SROTM More...
 

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
[in]N
          N is INTEGER
         number of elements in input vector(s)
[in,out]SX
          SX is REAL array, dimension N
         double precision vector with N elements
[in]INCX
          INCX is INTEGER
         storage spacing between elements of SX
[in,out]SY
          SY is REAL array, dimension N
         double precision vector with N elements
[in]INCY
          INCY is INTEGER
         storage spacing between elements of SY
[in,out]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.
Date
November 2011

Definition at line 100 of file srotm.f.

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