
NAMEztptri.f SYNOPSISFunctions/Subroutinessubroutine ztptri (UPLO, DIAG, N, AP, INFO) Function/Subroutine Documentationsubroutine ztptri (characterUPLO, characterDIAG, integerN, complex*16, dimension( * )AP, integerINFO)ZTPTRI Purpose:ZTPTRI computes the inverse of a complex upper or lower triangular matrix A stored in packed format. UPLO
Author:
UPLO is CHARACTER*1 = 'U': A is upper triangular; = 'L': A is lower triangular.DIAG DIAG is CHARACTER*1 = 'N': A is nonunit triangular; = 'U': A is unit triangular.N N is INTEGER The order of the matrix A. N >= 0.AP AP is COMPLEX*16 array, dimension (N*(N+1)/2) On entry, the upper or lower triangular matrix A, stored columnwise in a linear array. The jth column of A is stored in the array AP as follows: if UPLO = 'U', AP(i + (j1)*j/2) = A(i,j) for 1<=i<=j; if UPLO = 'L', AP(i + (j1)*((2*nj)/2) = A(i,j) for j<=i<=n. See below for further details. On exit, the (triangular) inverse of the original matrix, in the same packed storage format.INFO INFO is INTEGER = 0: successful exit < 0: if INFO = i, the ith argument had an illegal value > 0: if INFO = i, A(i,i) is exactly zero. The triangular matrix is singular and its inverse can not be computed. Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
November 2011
Further Details:
A triangular matrix A can be transferred to packed storage using one of the following program segments: UPLO = 'U': UPLO = 'L': JC = 1 JC = 1 DO 2 J = 1, N DO 2 J = 1, N DO 1 I = 1, J DO 1 I = J, N AP(JC+I1) = A(I,J) AP(JC+IJ) = A(I,J) 1 CONTINUE 1 CONTINUE JC = JC + J JC = JC + N  J + 1 2 CONTINUE 2 CONTINUE AuthorGenerated automatically by Doxygen for LAPACK from the source code.
Visit the GSP FreeBSD Man Page Interface. 