spptri.f man page

spptri.f

Synopsis

Functions/Subroutines

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

Function/Subroutine Documentation

subroutine spptri (character UPLO, integer N, real, dimension( * ) AP, integer INFO)

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:

December 2016

Definition at line 95 of file spptri.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page spptri(3) is an alias of spptri.f(3).

Tue Nov 14 2017 Version 3.8.0 LAPACK