purpose
compute a vector subscript for an element in a matrix of
specified storage mode
usage
call loc (i,j,ir,n,m,ms)
description of parameters
i - row number of element
j - column number of element
ir - resultant vector subscript
n - number of rows in matrix
m - number of columns in matrix
ms - one digit number for storage mode of matrix
0 - general
1 - symmetric
2 - diagonal
remarks
none
subroutines and function subprograms required
none
method
ms=0 subscript is computed for a matrix with n*m elements
in storage (general matrix)
ms=1 subscript is computed for a matrix with n*(n+1)/2 in
storage (upper triangle of symmetric matrix). if
element is in lower triangular portion, subscript is
corresponding element in upper triangle.
ms=2 subscript is computed for a matrix with n elements
in storage (diagonal elements of diagonal matrix).
if element is not on diagonal (and therefore not in
storage), ir is set to zero. |