SGECON estimates the reciprocal of the condition number of a general


 real matrix A, in either the 1-norm or the infinity-norm, using


 the LU factorization computed by SGETRF.


 An estimate is obtained for norm(inv(A)), and the reciprocal of the


 condition number is computed as


    RCOND = 1 / ( norm(A) * norm(inv(A)) ).

NORM

          NORM is 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.

N

          N is INTEGER


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

A

          A is REAL array, dimension (LDA,N)


          The factors L and U from the factorization A = P*L*U


          as computed by SGETRF.

LDA

          LDA is INTEGER


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

ANORM

          ANORM is REAL


          If NORM = '1' or 'O', the 1-norm of the original matrix A.


          If NORM = 'I', the infinity-norm of the original matrix A.

RCOND

          RCOND is REAL


          The reciprocal of the condition number of the matrix A,


          computed as RCOND = 1/(norm(A) * norm(inv(A))).

WORK

          WORK is REAL array, dimension (4*N)

IWORK

          IWORK is INTEGER array, dimension (N)

INFO

          INFO is INTEGER


          = 0:  successful exit


          < 0:  if INFO = -i, the i-th argument had an illegal value.


                NaNs are illegal values for ANORM, and they propagate to


                the output parameter RCOND.


                Infinity is illegal for ANORM, and it propagates to the output


                parameter RCOND as 0.


          = 1:  if RCOND = NaN, or


                   RCOND = Inf, or


                   the computed norm of the inverse of A is 0.


                In the latter, RCOND = 0 is returned.

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