CXML
        	    
LAPACK version 3.0
ctrcon(3)

PURPOSE
  CTRCON - estimate the reciprocal of the condition number of a triangular
  matrix A, in either the 1-norm or the infinity-norm

SYNTAX
  SUBROUTINE CTRCON( NORM, UPLO, DIAG, N, A, LDA, RCOND, WORK, RWORK, INFO )

      CHARACTER	     DIAG, NORM, UPLO

      INTEGER	     INFO, LDA, N

      REAL	     RCOND

      REAL	     RWORK( * )

      COMPLEX	     A( LDA, * ), WORK( * )

DESCRIPTION
  CTRCON estimates the reciprocal of the condition number of a triangular
  matrix A, in either the 1-norm or the infinity-norm.	The norm of A is
  computed and an estimate is obtained for norm(inv(A)), then the reciprocal
  of the condition number is computed as
     RCOND = 1 / ( norm(A) * norm(inv(A)) ).

ARGUMENTS
  NORM	  (input) CHARACTER*1
	  Specifies whether the 1-norm condition number or the infinity-norm
	  condition number is required:
	  = '1' or 'O':	 1-norm;
	  = 'I':	 Infinity-norm.

  UPLO	  (input) CHARACTER*1
	  = 'U':  A is upper triangular;
	  = 'L':  A is lower triangular.

  DIAG	  (input) CHARACTER*1
	  = 'N':  A is non-unit triangular;
	  = 'U':  A is unit triangular.

  N	  (input) INTEGER
	  The order of the matrix A.  N >= 0.

  A	  (input) COMPLEX array, dimension (LDA,N)
	  The triangular matrix A.  If UPLO = 'U', the leading N-by-N upper
	  triangular part of the array A contains the upper triangular
	  matrix, and the strictly lower triangular part of A is not
	  referenced.  If UPLO = 'L', the leading N-by-N lower triangular
	  part of the array A contains the lower triangular matrix, and the
	  strictly upper triangular part of A is not referenced.  If DIAG =
	  'U', the diagonal elements of A are also not referenced and are
	  assumed to be 1.

  LDA	  (input) INTEGER
	  The leading dimension of the array A.	 LDA >= max(1,N).

  RCOND	  (output) REAL
	  The reciprocal of the condition number of the matrix A, computed as
	  RCOND = 1/(norm(A) * norm(inv(A))).

  WORK	  (workspace) COMPLEX array, dimension (2*N)

  RWORK	  (workspace) REAL array, dimension (N)

  INFO	  (output) INTEGER
	  = 0:	successful exit
	  < 0:	if INFO = -i, the i-th argument had an illegal value