dcopym.f
SUBROUTINE DCOPYM (N, DX, INCX, DY, INCY)
C***BEGIN PROLOGUE DCOPYM
C***PURPOSE Copy the negative of a vector to a vector.
C***LIBRARY SLATEC (BLAS)
C***CATEGORY D1A5
C***TYPE DOUBLE PRECISION (SCOPYM-S, DCOPYM-D)
C***KEYWORDS BLAS, COPY, VECTOR
C***AUTHOR Kahaner, D. K., (NBS)
C***DESCRIPTION
C
C Description of Parameters
C The * Flags Output Variables
C
C N Number of elements in vector(s)
C DX Double precision vector with N elements
C INCX Storage spacing between elements of DX
C DY* Double precision negative copy of DX
C INCY Storage spacing between elements of DY
C
C *** Note that DY = -DX ***
C
C Copy negative of d.p. DX to d.p. DY. For I=0 to N-1,
C copy -DX(LX+I*INCX) to DY(LY+I*INCY), where LX=1 if
C INCX .GE. 0, else LX = 1+(1-N)*INCX, and LY is defined
C in a similar way using INCY.
C
C***REFERENCES (NONE)
C***ROUTINES CALLED (NONE)
C***REVISION HISTORY (YYMMDD)
C 801001 DATE WRITTEN
C 861211 REVISION DATE from Version 3.2
C 891214 Prologue converted to Version 4.0 format. (BAB)
C 920310 Corrected definition of LX in DESCRIPTION. (WRB)
C***END PROLOGUE DCOPYM