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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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subroutine cptts2 | ( | integer | IUPLO, |
integer | N, | ||
integer | NRHS, | ||
real, dimension( * ) | D, | ||
complex, dimension( * ) | E, | ||
complex, dimension( ldb, * ) | B, | ||
integer | LDB | ||
) |
CPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf.
Download CPTTS2 + dependencies [TGZ] [ZIP] [TXT]
CPTTS2 solves a tridiagonal system of the form A * X = B using the factorization A = U**H*D*U or A = L*D*L**H computed by CPTTRF. D is a diagonal matrix specified in the vector D, U (or L) is a unit bidiagonal matrix whose superdiagonal (subdiagonal) is specified in the vector E, and X and B are N by NRHS matrices.
[in] | IUPLO | IUPLO is INTEGER Specifies the form of the factorization and whether the vector E is the superdiagonal of the upper bidiagonal factor U or the subdiagonal of the lower bidiagonal factor L. = 1: A = U**H *D*U, E is the superdiagonal of U = 0: A = L*D*L**H, E is the subdiagonal of L |
[in] | N | N is INTEGER The order of the tridiagonal matrix A. N >= 0. |
[in] | NRHS | NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. |
[in] | D | D is REAL array, dimension (N) The n diagonal elements of the diagonal matrix D from the factorization A = U**H *D*U or A = L*D*L**H. |
[in] | E | E is COMPLEX array, dimension (N-1) If IUPLO = 1, the (n-1) superdiagonal elements of the unit bidiagonal factor U from the factorization A = U**H*D*U. If IUPLO = 0, the (n-1) subdiagonal elements of the unit bidiagonal factor L from the factorization A = L*D*L**H. |
[in,out] | B | B is COMPLEX array, dimension (LDB,NRHS) On entry, the right hand side vectors B for the system of linear equations. On exit, the solution vectors, X. |
[in] | LDB | LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N). |
Definition at line 115 of file cptts2.f.