SRC/dlange.f(3) Library Functions Manual 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. LAPACK Version 3.12.0 SRC/dlange.f(3)