spptri.f man page

spptri.f —

Synopsis

Functions/Subroutines

subroutine spptri (UPLO, N, AP, INFO)
SPPTRI

Function/Subroutine Documentation

subroutine spptri (characterUPLO, integerN, real, dimension( * )AP, integerINFO)

SPPTRI

Purpose:

SPPTRI computes the inverse of a real symmetric positive definite
matrix A using the Cholesky factorization A = U**T*U or A = L*L**T
computed by SPPTRF.

Parameters:

UPLO

UPLO is CHARACTER*1
= 'U':  Upper triangular factor is stored in AP;
= 'L':  Lower triangular factor is stored in AP.

N

N is INTEGER
The order of the matrix A.  N >= 0.

AP

AP is REAL array, dimension (N*(N+1)/2)
On entry, the triangular factor U or L from the Cholesky
factorization A = U**T*U or A = L*L**T, packed columnwise as
a linear array.  The j-th column of U or L is stored in the
array AP as follows:
if UPLO = 'U', AP(i + (j-1)*j/2) = U(i,j) for 1<=i<=j;
if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n.

On exit, the upper or lower triangle of the (symmetric)
inverse of A, overwriting the input factor U or L.

INFO

INFO is INTEGER
= 0:  successful exit
< 0:  if INFO = -i, the i-th argument had an illegal value
> 0:  if INFO = i, the (i,i) element of the factor U or L is
      zero, and the inverse could not be computed.

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

November 2011

Definition at line 94 of file spptri.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

spptri(3) is an alias of spptri.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK