dptsv
dptsv - compute the solution to a real system of linear equations A*X = B, where A is an N-by-N symmetric positive definite tridiagonal matrix, and X and B are N-by-NRHS matrices.
SUBROUTINE DPTSV( N, NRHS, DIAG, SUB, B, LDB, INFO)
INTEGER N, NRHS, LDB, INFO
DOUBLE PRECISION DIAG(*), SUB(*), B(LDB,*)
SUBROUTINE DPTSV_64( N, NRHS, DIAG, SUB, B, LDB, INFO)
INTEGER*8 N, NRHS, LDB, INFO
DOUBLE PRECISION DIAG(*), SUB(*), B(LDB,*)
SUBROUTINE PTSV( [N], [NRHS], DIAG, SUB, B, [LDB], [INFO])
INTEGER :: N, NRHS, LDB, INFO
REAL(8), DIMENSION(:) :: DIAG, SUB
REAL(8), DIMENSION(:,:) :: B
SUBROUTINE PTSV_64( [N], [NRHS], DIAG, SUB, B, [LDB], [INFO])
INTEGER(8) :: N, NRHS, LDB, INFO
REAL(8), DIMENSION(:) :: DIAG, SUB
REAL(8), DIMENSION(:,:) :: B
#include <sunperf.h>
void dptsv(int n, int nrhs, double *diag, double *sub, double *b, int ldb, int *info);
void dptsv_64(long n, long nrhs, double *diag, double *sub, double *b, long ldb, long *info);
dptsv computes the solution to a real system of linear equations
A*X = B, where A is an N-by-N symmetric positive definite tridiagonal
matrix, and X and B are N-by-NRHS matrices.
A is factored as A = L*D*L**T, and the factored form of A is then
used to solve the system of equations.
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* N (input)
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The order of the matrix A. N >= 0.
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* NRHS (input)
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The number of right hand sides, i.e., the number of columns
of the matrix B. NRHS >= 0.
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* DIAG (input/output)
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On entry, the n diagonal elements of the tridiagonal matrix
A. On exit, the n diagonal elements of the diagonal matrix
DIAG from the factorization A = L*DIAG*L**T.
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* SUB (input/output)
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On entry, the (n-1) subdiagonal elements of the tridiagonal
matrix A. On exit, the (n-1) subdiagonal elements of the
unit bidiagonal factor L from the L*DIAG*L**T factorization of
A. (SUB can also be regarded as the superdiagonal of the unit
bidiagonal factor U from the U**T*DIAG*U factorization of A.)
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* B (input/output)
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On entry, the N-by-NRHS right hand side matrix B.
On exit, if INFO = 0, the N-by-NRHS solution matrix X.
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* LDB (input)
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The leading dimension of the array B. LDB >= max(1,N).
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* INFO (output)
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