dynare/mex/sources/libslicot/UD01DD.f

139 lines
3.7 KiB
Fortran

SUBROUTINE UD01DD( M, N, NIN, A, LDA, INFO )
C
C SLICOT RELEASE 5.0.
C
C Copyright (c) 2002-2009 NICONET e.V.
C
C This program is free software: you can redistribute it and/or
C modify it under the terms of the GNU General Public License as
C published by the Free Software Foundation, either version 2 of
C the License, or (at your option) any later version.
C
C This program is distributed in the hope that it will be useful,
C but WITHOUT ANY WARRANTY; without even the implied warranty of
C MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
C GNU General Public License for more details.
C
C You should have received a copy of the GNU General Public License
C along with this program. If not, see
C <http://www.gnu.org/licenses/>.
C
C PURPOSE
C
C To read the elements of a sparse matrix.
C
C ARGUMENTS
C
C Input/Output Parameters
C
C M (input) INTEGER
C The number of rows of the matrix A. M >= 0.
C
C N (input) INTEGER
C The number of columns of the matrix A. N >= 0.
C
C NIN (input) INTEGER
C The input channel from which the elements of A are read.
C NIN >= 0.
C
C A (output) DOUBLE PRECISION array, dimension (LDA,N)
C The leading M-by-N part of this array contains the sparse
C matrix A. The not assigned elements are set to zero.
C
C LDA INTEGER
C The leading dimension of array A. LDA >= MAX(1,M).
C
C Error Indicator
C
C INFO INTEGER
C = 0: successful exit;
C < 0: if INFO = -i, the i-th argument had an illegal
C value;
C = 1 : if a row index i is read with i < 1 or i > M or
C a column index j is read with j < 1 or j > N.
C This is a warning.
C
C METHOD
C
C First, the elements A(i,j) with 1 <= i <= M and 1 <= j <= N are
C set to zero. Next the nonzero elements are read from the input
C file NIN. Each line of NIN must contain consecutively the values
C i, j, A(i,j). The routine terminates after the last line has been
C read.
C
C REFERENCES
C
C None.
C
C NUMERICAL ASPECTS
C
C None.
C
C CONTRIBUTOR
C
C Release 3.0: V. Sima, Katholieke Univ. Leuven, Belgium, June 1998.
C Based on routine RDSPAR by A.J. Geurts, Eindhoven University of
C Technology, Holland.
C
C REVISIONS
C
C -
C
C ******************************************************************
C
C .. Parameters ..
DOUBLE PRECISION ZERO
PARAMETER ( ZERO = 0.0D0 )
C .. Scalar Arguments ..
INTEGER INFO, LDA, M, N, NIN
C .. Array Arguments ..
DOUBLE PRECISION A(LDA,*)
C .. Local Scalars ..
INTEGER I, J
DOUBLE PRECISION AIJ
C .. External Subroutines ..
EXTERNAL DLASET, XERBLA
C .. Intrinsic Functions ..
INTRINSIC MAX
C
C .. Executable statements ..
C
INFO = 0
C
C Check the input scalar arguments.
C
IF( M.LT.0 ) THEN
INFO = -1
ELSE IF( N.LT.0 ) THEN
INFO = -2
ELSE IF( NIN.LT.0 ) THEN
INFO = -3
ELSE IF( LDA.LT.MAX( 1, M ) ) THEN
INFO = -5
END IF
C
IF ( INFO.NE.0 ) THEN
C
C Error return.
C
CALL XERBLA( 'UD01DD', -INFO )
RETURN
END IF
C
CALL DLASET( 'Full', M, N, ZERO, ZERO, A, LDA )
C
C Read (i, j, A(i,j)) of the nonzero elements one by one.
C
10 READ( NIN, FMT = *, END = 20 ) I, J, AIJ
IF ( I.LT.1 .OR. I.GT.M .OR. J.LT.1 .OR. J.GT.N ) THEN
INFO = 1
ELSE
A(I,J) = AIJ
END IF
GO TO 10
20 CONTINUE
C
RETURN
C *** Last line of UD01DD ***
END