C4.10. FMS Subroutine XXDSVM

RSDSVM
CHDSVM
CSDSVM

PURPOSE: Submatrix-Vectors Multiply

Multiply a group of vectors {X} by submatrices [S]i and place the results in vectors {Y}, according to the FMS Parameter IACCUM

{Y} = {Z} - SUM([S]i{X}), IACCUM = -1,


{Y} =       SUM([S]i{X}), IACCUM =  0, (default)


{Y} = {Z} + SUM([S]i{X}), IACCUM = +1,

SYNOPSIS


	CALL RSDSVM (LUS, NUMSF, LUX, LUY, NUMVEC, LUZ)

	CALL CHDSVM (LUS, NUMSF, LUX, LUY, NUMVEC, LUZ)

	CALL CSDSVM (LUS, NUMSF, LUX, LUY, NUMVEC, LUZ)

INPUT PARAMETERS:

LUS(10,NUMSF) = Integer array.
File attributes for each submatrix file.
NUMSF = Integer.
Number of submatrix files.
LUX(25) = Integer array.
File attributes for the file containing {X} vectors.
LUY(25) = Integer array.
File attributes for the file where the {Y} vectors are to be written. This parameter may be the same as LUX to overlay the {Y} vectors on the {X} vectors.
NUMVEC = Integer.
Number of vectors to multiply.
LUZ(25) = Integer array.
File attributes for the {Z} vectors. This parameter is only used if the FMS Parameter IACCUM is set to a nonzero value. This parameter may be the same as LUY to accumulate the results in {Y}.

OUTPUT PARAMETERS:

None.

FMS PARAMETERS:

The following FMS Parameters are especially important to this routine:

Parameter Description
IACCUM Product accumulation flag
= -1, {Y} = {Z} - SUM([S]i{X}), = 0, {Y} = SUM([S]i{X}), (default) = +1, {Y} = {Z} + SUM([S]i{X})

IPRMV Matrix-vectors multiply print code

Parameter	Description
IACCUM	Product accumulation flag = -1, {Y} = {Z} - SUM([S]i{X}), = 0, {Y} = SUM([S]i{X}), (default) = +1, {Y} = {Z} + SUM([S]i{X})
IPRMV	Matrix-vectors multiply print code

DESCRIPTION:

This subroutine multiplies a group of vectors {X} stored on file LUX by the submatrices stored on files LUS. The resulting vectors {Y} are written to file LUY, which may be the same as file LUX.

This subroutine is equivalent to assembling the matrix [A] with subroutines RSDA, RNDA, CHDA, CSDA, CNDA and then performing matrix-vectors multiply {Y}=[A]{X} using RSDMVM, RNDMVM, CHDMVM, CSDMVM, CNDMVM. If the assembled matrix [A] contains a large number of zero terms within the profile, this subroutine should be used. If the matrix is densely populated and several vectors are to be multiplied, the matrix [A] should be assembled as a separate step.