***PURPOSE Solve the real band system A*X=B or TRANS(A)*X=B using
the factors computed by DGBCO or DGBFA.
***CATEGORY D2A2
***TYPE DOUBLE PRECISION (SGBSL-S, DGBSL-D, CGBSL-C)
***KEYWORDS BANDED, LINEAR ALGEBRA, LINPACK, MATRIX, SOLVE
***AUTHOR Moler, C. B., (U. of New Mexico)
***DESCRIPTION
DGBSL solves the double precision band system
A * X = B or TRANS(A) * X = B
using the factors computed by DGBCO or DGBFA.
On Entry
ABD DOUBLE PRECISION(LDA, N)
the output from DGBCO or DGBFA.
LDA INTEGER
the leading dimension of the array ABD .
N INTEGER
the order of the original matrix.
ML INTEGER
number of diagonals below the main diagonal.
MU INTEGER
number of diagonals above the main diagonal.
IPVT INTEGER(N)
the pivot vector from DGBCO or DGBFA.
B DOUBLE PRECISION(N)
the right hand side vector.
JOB INTEGER
= 0 to solve A*X = B ,
= nonzero to solve TRANS(A)*X = B , where
TRANS(A) is the transpose.
On Return
B the solution vector X .
Error Condition
A division by zero will occur if the input factor contains a
zero on the diagonal. Technically this indicates singularity
but it is often caused by improper arguments or improper
setting of LDA . It will not occur if the subroutines are
called correctly and if DGBCO has set RCOND .GT. 0.0
or DGBFA has set INFO .EQ. 0 .
To compute INVERSE(A) * C where C is a matrix
with P columns
CALL DGBCO(ABD,LDA,N,ML,MU,IPVT,RCOND,Z)
IF (RCOND is too small) GO TO ...
DO 10 J = 1, P
CALL DGBSL(ABD,LDA,N,ML,MU,IPVT,C(1,J),0)
10 CONTINUE
***REFERENCES J. J. Dongarra, J. R. Bunch, C. B. Moler, and G. W.
Stewart, LINPACK Users' Guide, SIAM, 1979.
***ROUTINES CALLED DAXPY, DDOT
***REVISION HISTORY (YYMMDD)
780814 DATE WRITTEN
890531 Changed all specific intrinsics to generic. (WRB)
890831 Modified array declarations. (WRB)
890831 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)
900326 Removed duplicate information from DESCRIPTION section.
(WRB)
920501 Reformatted the REFERENCES section. (WRB)
***END PROLOGUE DGBSL
***FIRST EXECUTABLE STATEMENT DGBSL
Inheritance Hierarchy Namespace: DotNumerics.ODE.DVodeAssembly: DWSIM.MathOps.DotNumerics (in DWSIM.MathOps.DotNumerics.dll) Version: 1.0.0.0 (1.0.0.0)
Syntax The DGBSL type exposes the following members.
Constructors Methods | Name | Description |
---|
| Run |
***PURPOSE Solve the real band system A*X=B or TRANS(A)*X=B using
the factors computed by DGBCO or DGBFA.
***CATEGORY D2A2
***TYPE DOUBLE PRECISION (SGBSL-S, DGBSL-D, CGBSL-C)
***KEYWORDS BANDED, LINEAR ALGEBRA, LINPACK, MATRIX, SOLVE
***AUTHOR Moler, C. B., (U. of New Mexico)
***DESCRIPTION
DGBSL solves the double precision band system
A * X = B or TRANS(A) * X = B
using the factors computed by DGBCO or DGBFA.
On Entry
ABD DOUBLE PRECISION(LDA, N)
the output from DGBCO or DGBFA.
LDA INTEGER
the leading dimension of the array ABD .
N INTEGER
the order of the original matrix.
ML INTEGER
number of diagonals below the main diagonal.
MU INTEGER
number of diagonals above the main diagonal.
IPVT INTEGER(N)
the pivot vector from DGBCO or DGBFA.
B DOUBLE PRECISION(N)
the right hand side vector.
JOB INTEGER
= 0 to solve A*X = B ,
= nonzero to solve TRANS(A)*X = B , where
TRANS(A) is the transpose.
On Return
B the solution vector X .
Error Condition
A division by zero will occur if the input factor contains a
zero on the diagonal. Technically this indicates singularity
but it is often caused by improper arguments or improper
setting of LDA . It will not occur if the subroutines are
called correctly and if DGBCO has set RCOND .GT. 0.0
or DGBFA has set INFO .EQ. 0 .
To compute INVERSE(A) * C where C is a matrix
with P columns
CALL DGBCO(ABD,LDA,N,ML,MU,IPVT,RCOND,Z)
IF (RCOND is too small) GO TO ...
DO 10 J = 1, P
CALL DGBSL(ABD,LDA,N,ML,MU,IPVT,C(1,J),0)
10 CONTINUE
***REFERENCES J. J. Dongarra, J. R. Bunch, C. B. Moler, and G. W.
Stewart, LINPACK Users' Guide, SIAM, 1979.
***ROUTINES CALLED DAXPY, DDOT
***REVISION HISTORY (YYMMDD)
780814 DATE WRITTEN
890531 Changed all specific intrinsics to generic. (WRB)
890831 Modified array declarations. (WRB)
890831 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)
900326 Removed duplicate information from DESCRIPTION section.
(WRB)
920501 Reformatted the REFERENCES section. (WRB)
***END PROLOGUE DGBSL
***FIRST EXECUTABLE STATEMENT DGBSL
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