.TH "SRC/zpttrf.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/zpttrf.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBzpttrf\fP (n, d, e, info)" .br .RI "\fBZPTTRF\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine zpttrf (integer n, double precision, dimension( * ) d, complex*16, dimension( * ) e, integer info)" .PP \fBZPTTRF\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> ZPTTRF computes the L*D*L**H factorization of a complex Hermitian !> positive definite tridiagonal matrix A\&. The factorization may also !> be regarded as having the form A = U**H *D*U\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIN\fP .PP .nf !> N is INTEGER !> The order of the matrix A\&. N >= 0\&. !> .fi .PP .br \fID\fP .PP .nf !> 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**H factorization of A\&. !> .fi .PP .br \fIE\fP .PP .nf !> E is COMPLEX*16 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**H factorization of A\&. !> E can also be regarded as the superdiagonal of the unit !> bidiagonal factor U from the U**H *D*U factorization of A\&. !> .fi .PP .br \fIINFO\fP .PP .nf !> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -k, the k-th argument had an illegal value !> > 0: if INFO = k, the leading principal minor of order k !> is not positive; if k < N, the factorization could not !> be completed, while if k = N, the factorization was !> completed, but D(N) <= 0\&. !> .fi .PP .RE .PP \fBAuthor\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP .PP Definition at line \fB91\fP of file \fBzpttrf\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.