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CentOS 7.0 - man page for dpttrf (centos section 3)

dpttrf.f(3)							      LAPACK							       dpttrf.f(3)

NAME
dpttrf.f -
SYNOPSIS
Functions/Subroutines subroutine dpttrf (N, D, E, INFO) DPTTRF Function/Subroutine Documentation subroutine dpttrf (integerN, double precision, dimension( * )D, double precision, dimension( * )E, integerINFO) DPTTRF Purpose: DPTTRF computes the L*D*L**T factorization of a real symmetric positive definite tridiagonal matrix A. The factorization may also be regarded as having the form A = U**T*D*U. Parameters: N N is INTEGER The order of the matrix A. N >= 0. D D is DOUBLE PRECISION array, dimension (N) On entry, the n diagonal elements of the tridiagonal matrix A. On exit, the n diagonal elements of the diagonal matrix D from the L*D*L**T factorization of A. E E is DOUBLE PRECISION array, dimension (N-1) 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*D*L**T factorization of A. E can also be regarded as the superdiagonal of the unit bidiagonal factor U from the U**T*D*U factorization of A. INFO INFO is INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value > 0: if INFO = k, the leading minor of order k is not positive definite; if k < N, the factorization could not be completed, while if k = N, the factorization was completed, but D(N) <= 0. Author: Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Date: September 2012 Definition at line 92 of file dpttrf.f. Author Generated automatically by Doxygen for LAPACK from the source code. Version 3.4.2 Tue Sep 25 2012 dpttrf.f(3)