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

6       SLANSP  -  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  sym‐
8       metric matrix A, supplied in packed form
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SYNOPSIS

11       REAL FUNCTION SLANSP( NORM, UPLO, N, AP, WORK )
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13           CHARACTER NORM, UPLO
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15           INTEGER   N
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17           REAL      AP( * ), WORK( * )
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PURPOSE

20       SLANSP   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 symmetric matrix A,  supplied in packed form.
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DESCRIPTION

26       SLANSP returns the value
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28          SLANSP = ( 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 SLANSP as described
46               above.
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48       UPLO    (input) CHARACTER*1
49               Specifies whether the upper or lower  triangular  part  of  the
50               symmetric  matrix A is supplied.  = 'U':  Upper triangular part
51               of A is supplied
52               = 'L':  Lower triangular part of A is supplied
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54       N       (input) INTEGER
55               The order of the matrix A.  N >= 0.  When N = 0, SLANSP is  set
56               to zero.
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58       AP      (input) REAL array, dimension (N*(N+1)/2)
59               The  upper  or lower triangle of the symmetric matrix A, packed
60               columnwise in a linear array.  The j-th column of A  is  stored
61               in  the array AP as follows: if UPLO = 'U', AP(i + (j-1)*j/2) =
62               A(i,j) for 1<=i<=j; if UPLO = 'L',  AP(i  +  (j-1)*(2n-j)/2)  =
63               A(i,j) for j<=i<=n.
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65       WORK    (workspace) REAL array, dimension (MAX(1,LWORK)),
66               where LWORK >= N when NORM = 'I' or '1' or 'O'; otherwise, WORK
67               is not referenced.
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71 LAPACK auxiliary routine (versionNo3v.e1m)ber 2006                       SLANSP(1)