Provided by: liblapack-doc_3.3.1-1_all bug

NAME

       LAPACK-3 - DLA_GBRCOND Estimate the Skeel condition number of op(A) * op2(C)  where op2 is
       determined by CMODE as follows  CMODE = 1 op2(C) = C  CMODE = 0 op2(C) =  I   CMODE  =  -1
       op2(C)  = inv(C)  The Skeel condition number cond(A) = norminf( |inv(A)||A| )  is computed
       by computing scaling factors  R  such  that   diag(R)*A*op2(C)  is  row  equilibrated  and
       computing the standard  infinity-norm condition number

SYNOPSIS

       DOUBLE PRECISION FUNCTION  DLA_GBRCOND(  TRANS,  N,  KL,  KU,  AB, LDAB, AFB, LDAFB, IPIV,
                        CMODE, C, INFO, WORK, IWORK )

           IMPLICIT     NONE

           CHARACTER    TRANS

           INTEGER      N, LDAB, LDAFB, INFO, KL, KU, CMODE

           INTEGER      IWORK( * ), IPIV( * )

           DOUBLE       PRECISION AB( LDAB, * ), AFB( LDAFB, * ), WORK( * ), C( * )

PURPOSE

          DLA_GBRCOND Estimates the Skeel condition number of  op(A) * op2(C)
          where op2 is determined by CMODE as follows
          CMODE =  1    op2(C) = C
          CMODE =  0    op2(C) = I
          CMODE = -1    op2(C) = inv(C)
          The Skeel condition number  cond(A) = norminf( |inv(A)||A| )
          is computed by computing scaling factors R such that
          diag(R)*A*op2(C) is row equilibrated and computing the standard
          infinity-norm condition number.

ARGUMENTS

        TRANS   (input) CHARACTER*1
                Specifies the form of the system of equations:
                = 'N':  A * X = B     (No transpose)
                = 'T':  A**T * X = B  (Transpose)
                = 'C':  A**H * X = B  (Conjugate Transpose = Transpose)

        N       (input) INTEGER
                The number of linear equations, i.e., the order of the
                matrix A.  N >= 0.

        KL      (input) INTEGER
                The number of subdiagonals within the band of A.  KL >= 0.

        KU      (input) INTEGER
                The number of superdiagonals within the band of A.  KU >= 0.

        AB      (input) DOUBLE PRECISION array, dimension (LDAB,N)
                On entry, the matrix A in band storage, in rows 1 to KL+KU+1.
                The j-th column of A is stored in the j-th column of the
                array AB as follows:
                AB(KU+1+i-j,j) = A(i,j) for max(1,j-KU)<=i<=min(N,j+kl)

        LDAB    (input) INTEGER
                The leading dimension of the array AB.  LDAB >= KL+KU+1.

        AFB     (input) DOUBLE PRECISION array, dimension (LDAFB,N)
                Details of the LU factorization of the band matrix A, as
                computed by DGBTRF.  U is stored as an upper triangular
                band matrix with KL+KU superdiagonals in rows 1 to KL+KU+1,
                and the multipliers used during the factorization are stored
                in rows KL+KU+2 to 2*KL+KU+1.

        LDAFB   (input) INTEGER
                The leading dimension of the array AFB.  LDAFB >= 2*KL+KU+1.

        IPIV    (input) INTEGER array, dimension (N)
                The pivot indices from the factorization A = P*L*U
                as computed by DGBTRF; row i of the matrix was interchanged
                with row IPIV(i).

        CMODE   (input) INTEGER
                Determines op2(C) in the formula op(A) * op2(C) as follows:
                CMODE =  1    op2(C) = C
                CMODE =  0    op2(C) = I
                CMODE = -1    op2(C) = inv(C)

        C       (input) DOUBLE PRECISION array, dimension (N)
                The vector C in the formula op(A) * op2(C).

        INFO    (output) INTEGER
                = 0:  Successful exit.
                i > 0:  The ith argument is invalid.

        WORK    (input) DOUBLE PRECISION array, dimension (5*N).
                Workspace.

        IWORK   (input) INTEGER array, dimension (N).
                Workspace.

    LAPACK routine (version 3.2.2)          April 2011                       DLA_GBRCOND(3lapack)