Purpose
To read the elements of a sparse matrix.Specification
SUBROUTINE UD01DD( M, N, NIN, A, LDA, INFO )
C .. Scalar Arguments ..
INTEGER INFO, LDA, M, N, NIN
C .. Array Arguments ..
DOUBLE PRECISION A(LDA,*)
Arguments
Input/Output Parameters
M (input) INTEGER
The number of rows of the matrix A. M >= 0.
N (input) INTEGER
The number of columns of the matrix A. N >= 0.
NIN (input) INTEGER
The input channel from which the elements of A are read.
NIN >= 0.
A (output) DOUBLE PRECISION array, dimension (LDA,N)
The leading M-by-N part of this array contains the sparse
matrix A. The not assigned elements are set to zero.
LDA INTEGER
The leading dimension of array A. LDA >= MAX(1,M).
Error Indicator
INFO INTEGER
= 0: successful exit;
< 0: if INFO = -i, the i-th argument had an illegal
value;
= 1 : if a row index i is read with i < 1 or i > M or
a column index j is read with j < 1 or j > N.
This is a warning.
Method
First, the elements A(i,j) with 1 <= i <= M and 1 <= j <= N are set to zero. Next the nonzero elements are read from the input file NIN. Each line of NIN must contain consecutively the values i, j, A(i,j). The routine terminates after the last line has been read.References
None.Numerical Aspects
None.Further Comments
NoneExample
Program Text
* UD01DD EXAMPLE PROGRAM TEXT
* Copyright (c) 2002-2010 NICONET e.V.
*
* .. Parameters ..
INTEGER NIN, NOUT
PARAMETER ( NIN = 5, NOUT = 6 )
INTEGER MMAX, NMAX
PARAMETER ( MMAX = 10, NMAX = 10 )
INTEGER LDA
PARAMETER ( LDA = NMAX )
* .. Local Scalars ..
INTEGER INFO, INFO1, M, N
* .. Local Arrays ..
DOUBLE PRECISION A(LDA,NMAX)
* .. External Subroutines ..
EXTERNAL UD01DD, UD01MD
* .. Executable Statements ..
*
WRITE ( NOUT, FMT = 99999 )
* Skip the heading in the data file and read the data.
READ ( NIN, FMT = '()' )
READ ( NIN, FMT = * ) M, N
IF ( M.LT.0 .OR. M.GT.MMAX ) THEN
WRITE ( NOUT, FMT = 99994 ) M
ELSE IF ( N.LT.0 .OR. N.GT.NMAX ) THEN
WRITE ( NOUT, FMT = 99995 ) N
ELSE
* Read the coefficients of the matrix polynomial P(s).
CALL UD01DD( M, N, NIN, A, LDA, INFO )
IF ( INFO.GE.0 ) THEN
* Write the matrix A.
CALL UD01MD( M, N, 5, NOUT, A, LDA, ' Matrix A', INFO1 )
IF ( INFO1.NE.0 )
$ WRITE ( NOUT, FMT = 99998 ) INFO1
END IF
IF ( INFO.NE.0 )
$ WRITE ( NOUT, FMT = 99997 ) INFO
END IF
STOP
*
99999 FORMAT (' UD01DD EXAMPLE PROGRAM RESULTS', /1X)
99998 FORMAT (' INFO on exit from UD01MD = ',I2)
99997 FORMAT (' INFO on exit from UD01DD = ',I2)
99995 FORMAT (/' N is out of range.',/' N = ',I5)
99994 FORMAT (/' M is out of range.',/' M = ',I5)
END
Program Data
UD01DD EXAMPLE PROGRAM DATA 6 5 1 1 -1.1 6 1 1.5 2 2 -2.2 6 2 2.5 3 3 -3.3 6 3 3.5 4 4 -4.4 6 4 4.5 5 5 -5.5 6 5 5.5Program Results
UD01DD EXAMPLE PROGRAM RESULTS
Matrix A ( 6X 5)
1 2 3 4 5
1 -0.1100000D+01 0.0000000D+00 0.0000000D+00 0.0000000D+00 0.0000000D+00
2 0.0000000D+00 -0.2200000D+01 0.0000000D+00 0.0000000D+00 0.0000000D+00
3 0.0000000D+00 0.0000000D+00 -0.3300000D+01 0.0000000D+00 0.0000000D+00
4 0.0000000D+00 0.0000000D+00 0.0000000D+00 -0.4400000D+01 0.0000000D+00
5 0.0000000D+00 0.0000000D+00 0.0000000D+00 0.0000000D+00 -0.5500000D+01
6 0.1500000D+01 0.2500000D+01 0.3500000D+01 0.4500000D+01 0.5500000D+01
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