1CTRTRI(1)                LAPACK routine (version 3.2)                CTRTRI(1)
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NAME

6       CTRTRI  -  computes  the inverse of a complex upper or lower triangular
7       matrix A
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SYNOPSIS

10       SUBROUTINE CTRTRI( UPLO, DIAG, N, A, LDA, INFO )
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12           CHARACTER      DIAG, UPLO
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14           INTEGER        INFO, LDA, N
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16           COMPLEX        A( LDA, * )
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PURPOSE

19       CTRTRI computes the inverse of a  complex  upper  or  lower  triangular
20       matrix A.  This is the Level 3 BLAS version of the algorithm.
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ARGUMENTS

23       UPLO    (input) CHARACTER*1
24               = 'U':  A is upper triangular;
25               = 'L':  A is lower triangular.
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27       DIAG    (input) CHARACTER*1
28               = 'N':  A is non-unit triangular;
29               = 'U':  A is unit triangular.
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31       N       (input) INTEGER
32               The order of the matrix A.  N >= 0.
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34       A       (input/output) COMPLEX array, dimension (LDA,N)
35               On  entry, the triangular matrix A.  If UPLO = 'U', the leading
36               N-by-N upper triangular part of the array A contains the  upper
37               triangular  matrix, and the strictly lower triangular part of A
38               is not referenced.  If UPLO = 'L',  the  leading  N-by-N  lower
39               triangular  part  of  the array A contains the lower triangular
40               matrix, and the strictly upper triangular part of A is not ref‐
41               erenced.   If  DIAG  = 'U', the diagonal elements of A are also
42               not referenced and are assumed to be 1.  On exit, the (triangu‐
43               lar)  inverse  of the original matrix, in the same storage for‐
44               mat.
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46       LDA     (input) INTEGER
47               The leading dimension of the array A.  LDA >= max(1,N).
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49       INFO    (output) INTEGER
50               = 0: successful exit
51               < 0: if INFO = -i, the i-th argument had an illegal value
52               > 0: if INFO = i,  A(i,i)  is  exactly  zero.   The  triangular
53               matrix is singular and its inverse can not be computed.
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57 LAPACK routine (version 3.2)    November 2008                       CTRTRI(1)
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