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

Chapter 15 Sparse Eigenvalues and Eigenvectors 1043
Matrix structure input by single entry DSEVI1
Name DSEVI1
Matrix structure input by single entry
Purpose This subprogram adds a single entry in the (irow, jcol) position in the lower
triangle to the set of known nonzeros for one of the sparse matrices.
Usage VECLIB:
CHARACTER*1 matrix
INTEGER*4 irow, jcol, ier
REAL*8 global(150)
CALL DSEVI1(matrix, irow, jcol, global, ier)
VECLIB8:
CHARACTER*1 matrix
INTEGER*8 irow, jcol, ier
REAL*8 global(150)
CALL DSEVI1(matrix, irow, jcol, 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.
irow Row index of the nonzero entry, jcol ≤ irow ≤ norder,
where norder is the matrix order specified in the call to
DSEVIN. Input of diagonal entries is optional.
jcol Column index of the nonzero entry, 1 ≤ jcol ≤ norder.
Updated global Global communications array for this problem. This
array must be passed, untouched by the user, to
successive subroutines in this package.