1SLANGE(1)           LAPACK auxiliary routine (version 3.1)           SLANGE(1)
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NAME

6       SLANGE  -  the  value  of  the  one norm, or the Frobenius norm, or the
7       infinity norm, or the element of  largest  absolute  value  of  a  real
8       matrix A
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SYNOPSIS

11       REAL FUNCTION SLANGE( NORM, M, N, A, LDA, WORK )
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13           CHARACTER NORM
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15           INTEGER   LDA, M, N
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17           REAL      A( LDA, * ), WORK( * )
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PURPOSE

20       SLANGE   returns  the value of the one norm,  or the Frobenius norm, or
21       the  infinity norm,  or the  element of  largest absolute value   of  a
22       real matrix A.
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DESCRIPTION

26       SLANGE returns the value
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28          SLANGE = ( max(abs(A(i,j))), NORM = 'M' or 'm'
29                   (
30                   ( norm1(A),         NORM = '1', 'O' or 'o'
31                   (
32                   ( normI(A),         NORM = 'I' or 'i'
33                   (
34                   ( normF(A),         NORM = 'F', 'f', 'E' or 'e'
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36       where   norm1   denotes the  one norm of a matrix (maximum column sum),
37       normI  denotes the  infinity norm  of a matrix  (maximum row  sum)  and
38       normF   denotes  the  Frobenius norm of a matrix (square root of sum of
39       squares).  Note that  max(abs(A(i,j)))   is  not  a  consistent  matrix
40       norm.
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ARGUMENTS

44       NORM    (input) CHARACTER*1
45               Specifies  the  value  to  be  returned  in SLANGE as described
46               above.
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48       M       (input) INTEGER
49               The number of rows of the matrix A.  M  >=  0.   When  M  =  0,
50               SLANGE is set to zero.
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52       N       (input) INTEGER
53               The  number  of  columns of the matrix A.  N >= 0.  When N = 0,
54               SLANGE is set to zero.
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56       A       (input) REAL array, dimension (LDA,N)
57               The m by n matrix A.
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59       LDA     (input) INTEGER
60               The leading dimension of the array A.  LDA >= max(M,1).
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62       WORK    (workspace) REAL array, dimension (MAX(1,LWORK)),
63               where LWORK >= M when NORM = 'I'; otherwise, WORK is not refer‐
64               enced.
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68 LAPACK auxiliary routine (versionNo3v.e1m)ber 2006                       SLANGE(1)
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