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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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subroutine cgtt01 | ( | integer | N, |
complex, dimension( * ) | DL, | ||
complex, dimension( * ) | D, | ||
complex, dimension( * ) | DU, | ||
complex, dimension( * ) | DLF, | ||
complex, dimension( * ) | DF, | ||
complex, dimension( * ) | DUF, | ||
complex, dimension( * ) | DU2, | ||
integer, dimension( * ) | IPIV, | ||
complex, dimension( ldwork, * ) | WORK, | ||
integer | LDWORK, | ||
real, dimension( * ) | RWORK, | ||
real | RESID | ||
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CGTT01
CGTT01 reconstructs a tridiagonal matrix A from its LU factorization and computes the residual norm(L*U - A) / ( norm(A) * EPS ), where EPS is the machine epsilon.
[in] | N | N is INTEGTER The order of the matrix A. N >= 0. |
[in] | DL | DL is COMPLEX array, dimension (N-1) The (n-1) sub-diagonal elements of A. |
[in] | D | D is COMPLEX array, dimension (N) The diagonal elements of A. |
[in] | DU | DU is COMPLEX array, dimension (N-1) The (n-1) super-diagonal elements of A. |
[in] | DLF | DLF is COMPLEX array, dimension (N-1) The (n-1) multipliers that define the matrix L from the LU factorization of A. |
[in] | DF | DF is COMPLEX array, dimension (N) The n diagonal elements of the upper triangular matrix U from the LU factorization of A. |
[in] | DUF | DUF is COMPLEX array, dimension (N-1) The (n-1) elements of the first super-diagonal of U. |
[in] | DU2 | DU2 is COMPLEX array, dimension (N-2) The (n-2) elements of the second super-diagonal of U. |
[in] | IPIV | IPIV is INTEGER array, dimension (N) The pivot indices; for 1 <= i <= n, row i of the matrix was interchanged with row IPIV(i). IPIV(i) will always be either i or i+1; IPIV(i) = i indicates a row interchange was not required. |
[out] | WORK | WORK is COMPLEX array, dimension (LDWORK,N) |
[in] | LDWORK | LDWORK is INTEGER The leading dimension of the array WORK. LDWORK >= max(1,N). |
[out] | RWORK | RWORK is REAL array, dimension (N) |
[out] | RESID | RESID is REAL The scaled residual: norm(L*U - A) / (norm(A) * EPS) |
Definition at line 136 of file cgtt01.f.