1SROTM(1)                         BLAS routine                         SROTM(1)
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NAME

6       SROTM  -  THE  MODIFIED  GIVENS TRANSFORMATION, H, TO THE 2 BY N MATRIX
7       (SX**T) , WHERE **T INDICATES TRANSPOSE
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SYNOPSIS

10       SUBROUTINE SROTM(N,SX,INCX,SY,INCY,SPARAM)
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12           INTEGER                                INCX,INCY,N
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14           REAL                                   SPARAM(5),SX(1),SY(1)
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PURPOSE

17          APPLY THE MODIFIED GIVENS TRANSFORMATION, H, TO THE 2 BY N MATRIX
18          (DX**T)
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20          SX(LX+I*INCX), I = 0 TO N-1, WHERE LX = 1 IF INCX .GE. 0, ELSE
21          LX = (-INCX)*N, AND SIMILARLY FOR SY USING USING LY AND INCY.
22          WITH SPARAM(1)=SFLAG, H HAS ONE OF THE FOLLOWING FORMS..
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24          SFLAG=-1.E0     SFLAG=0.E0        SFLAG=1.E0     SFLAG=-2.E0
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26            (SH11  SH12)    (1.E0  SH12)    (SH11  1.E0)    (1.E0  0.E0)
27          H=(          )    (          )    (          )    (          )
28            (SH21  SH22),   (SH21  1.E0),   (-1.E0 SH22),   (0.E0  1.E0).
29          SEE  SROTMG FOR A DESCRIPTION OF DATA STORAGE IN SPARAM.
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ARGUMENTS

34       N      (input) INTEGER
35              number of elements in input vector(s)
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37       SX     (input/output) REAL array, dimension N
38              double precision vector with 5 elements
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40       INCX   (input) INTEGER
41              storage spacing between elements of SX
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43       SY     (input/output) REAL array, dimension N
44              double precision vector with N elements
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46       INCY   (input) INTEGER
47              storage spacing between elements of SY
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49              SPARAM (input/output)  REAL array, dimension  5  SPARAM(1)=SFLAG
50              SPARAM(2)=SH11 SPARAM(3)=SH21 SPARAM(4)=SH12 SPARAM(5)=SH22
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54BLAS routine                     February 2007                        SROTM(1)