SRC/dlange.f(3)

NAME
SRC/dlange.f

SYNOPSIS

  Functions/Subroutines
double precision function dlange (norm, m, n, a, lda, work)
DLANGE returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general rectangular matrix.

Function/Subroutine Documentation

  double precision function dlange (character norm, integer m, integer n, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( * ) work)

DLANGE returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general rectangular matrix.

Purpose:

     DLANGE  returns the value of the one norm,  or the Frobenius norm, or
     the  infinity norm,  or the  element of  largest absolute value  of a
     real matrix A.

Returns
    DLANGE

        DLANGE = ( max(abs(A(i,j))), NORM = 'M' or 'm'
                 (
                 ( norm1(A),         NORM = '1', 'O' or 'o'
                 (
                 ( normI(A),         NORM = 'I' or 'i'
                 (
                 ( normF(A),         NORM = 'F', 'f', 'E' or 'e'
     where  norm1  denotes the  one norm of a matrix (maximum column sum),
     normI  denotes the  infinity norm  of a matrix  (maximum row sum) and
     normF  denotes the  Frobenius norm of a matrix (square root of sum of
     squares).  Note that  max(abs(A(i,j)))  is not a consistent matrix norm.

Parameters
    NORM

              NORM is CHARACTER*1
              Specifies the value to be returned in DLANGE as described
              above.

    M

              M is INTEGER
              The number of rows of the matrix A.  M >= 0.  When M = 0,
              DLANGE is set to zero.

    N

              N is INTEGER
              The number of columns of the matrix A.  N >= 0.  When N = 0,
              DLANGE is set to zero.

    A

              A is DOUBLE PRECISION array, dimension (LDA,N)
              The m by n matrix A.

    LDA

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

    WORK

              WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)),
              where LWORK >= M when NORM = 'I'; otherwise, WORK is not
              referenced.

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 113 of file dlange.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.