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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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subroutine cptt01 | ( | integer | N, |
real, dimension( * ) | D, | ||
complex, dimension( * ) | E, | ||
real, dimension( * ) | DF, | ||
complex, dimension( * ) | EF, | ||
complex, dimension( * ) | WORK, | ||
real | RESID | ||
) |
CPTT01
CPTT01 reconstructs a tridiagonal matrix A from its L*D*L' factorization and computes the residual norm(L*D*L' - A) / ( n * norm(A) * EPS ), where EPS is the machine epsilon.
[in] | N | N is INTEGTER The order of the matrix A. |
[in] | D | D is REAL array, dimension (N) The n diagonal elements of the tridiagonal matrix A. |
[in] | E | E is COMPLEX array, dimension (N-1) The (n-1) subdiagonal elements of the tridiagonal matrix A. |
[in] | DF | DF is REAL array, dimension (N) The n diagonal elements of the factor L from the L*D*L' factorization of A. |
[in] | EF | EF is COMPLEX array, dimension (N-1) The (n-1) subdiagonal elements of the factor L from the L*D*L' factorization of A. |
[out] | WORK | WORK is COMPLEX array, dimension (2*N) |
[out] | RESID | RESID is REAL norm(L*D*L' - A) / (n * norm(A) * EPS) |
Definition at line 94 of file cptt01.f.