GNU/Linux man pages
Livre :
Expressions régulières,
Syntaxe et mise en oeuvre :
GNU/Linux |
CentOS 4.8 |
i386 |
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spttrs(l) |
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SPTTRS - solve a tridiagonal system of the form A * X = B using the L*D*L’ factorization of A computed by SPTTRF
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SUBROUTINE SPTTRS( |
N, NRHS, D, E, B, LDB, INFO ) |
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INTEGER |
INFO, LDB, N, NRHS |
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REAL |
B( LDB, * ), D( * ), E( * ) |
SPTTRS solves a tridiagonal system of the form A * X = B using the L*D*L’ factorization of A computed by SPTTRF. D is a diagonal matrix specified in the vector D, L is a unit bidiagonal matrix whose subdiagonal is specified in the vector E, and X and B are N by NRHS matrices.
N (input) INTEGER
The order of the tridiagonal matrix A. N >= 0.
NRHS (input) INTEGER
The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.
D (input) REAL array, dimension (N)
The n diagonal elements of the diagonal matrix D from the L*D*L’ factorization of A.
E (input) REAL array, dimension (N-1)
The (n-1) subdiagonal elements of the unit bidiagonal factor L from the L*D*L’ factorization of A. E can also be regarded as the superdiagonal of the unit bidiagonal factor U from the factorization A = U’*D*U.
B (input/output) REAL array, dimension (LDB,NRHS)
On entry, the right hand side vectors B for the system of linear equations. On exit, the solution vectors, X.
LDB (input) INTEGER
The leading dimension of the array B. LDB >= max(1,N).
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -k, the k-th argument had an illegal
value
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spttrs(l) | |