dscal.f
SUBROUTINE DSCAL (N, DA, DX, INCX)
C***BEGIN PROLOGUE DSCAL
C***PURPOSE Multiply a vector by a constant.
C***LIBRARY SLATEC (BLAS)
C***CATEGORY D1A6
C***TYPE DOUBLE PRECISION (SSCAL-S, DSCAL-D, CSCAL-C)
C***KEYWORDS BLAS, LINEAR ALGEBRA, SCALE, VECTOR
C***AUTHOR Lawson, C. L., (JPL)
C Hanson, R. J., (SNLA)
C Kincaid, D. R., (U. of Texas)
C Krogh, F. T., (JPL)
C***DESCRIPTION
C
C B L A S Subprogram
C Description of Parameters
C
C --Input--
C N number of elements in input vector(s)
C DA double precision scale factor
C DX double precision vector with N elements
C INCX storage spacing between elements of DX
C
C --Output--
C DX double precision result (unchanged if N.LE.0)
C
C Replace double precision DX by double precision DA*DX.
C For I = 0 to N-1, replace DX(IX+I*INCX) with DA * DX(IX+I*INCX),
C where IX = 1 if INCX .GE. 0, else IX = 1+(1-N)*INCX.
C
C***REFERENCES C. L. Lawson, R. J. Hanson, D. R. Kincaid and F. T.
C Krogh, Basic linear algebra subprograms for Fortran
C usage, Algorithm No. 539, Transactions on Mathematical
C Software 5, 3 (September 1979), pp. 308-323.
C***ROUTINES CALLED (NONE)
C***REVISION HISTORY (YYMMDD)
C 791001 DATE WRITTEN
C 890831 Modified array declarations. (WRB)
C 890831 REVISION DATE from Version 3.2
C 891214 Prologue converted to Version 4.0 format. (BAB)
C 900821 Modified to correct problem with a negative increment.
C (WRB)
C 920501 Reformatted the REFERENCES section. (WRB)
C***END PROLOGUE DSCAL