HP MLIB User's Guide Vol. 2 7th Ed.

1050 HP MLIB User’s Guide
DSEVIM Matrix structure input by matrix
Name DSEVIM
Matrix structure input by matrix
Purpose This subprogram specifies the locations of all of the nonzeros in the lower
triangle of one of the matrices.
Usage VECLIB:
CHARACTER*1 matrix
INTEGER*4 norder, nnzero, colstr(norder+1), rowind(nnzero), ier
REAL*8 global(150)
CALL DSEVIM(matrix, colstr, rowind, global, ier)
VECLIB8:
CHARACTER*1 matrix
INTEGER*8 norder, nnzero, colstr(norder+1), rowind(nnzero), ier
REAL*8 global(150)
CALL DSEVIM(matrix, colstr, rowind, global, ier)
Input matrix Character string denoting the matrix for which the
nonzero location is being input:
’A’ or ’a’ or
’K’ or ’k’ Add nonzero to the matrix on the left
side.
’B’ or ’b’ or
’M’ or ’m’ Add nonzero to the matrix on the right
side.
colstr colstr(j) gives the address in rowind of the first
nonzero in the lower triangular part of column j of the
matrix specified by matrix. All of the nonzeros for
column j are found in ascending order in
rowind(colstr(j)), rowind(colstr(j)+1), ...,
rowind(colstr(j+1)−1).
colstr(norder+1) must be set to one greater than the
total number of nonzeros, nnzero in the lower
triangular part of the matrix, where norder is the
matrix order as specified in the call to DSEVIN.
rowind List of row indices for all nonzeros in ascending order
within each column in the lower triangle part of the
matrix designated by matrix. Input of diagonal entries
is optional.