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.TH SLANSP l "15 June 2000" "LAPACK version 3.0" ")"
.SH NAME
SLANSP - return the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a real symmetric matrix A, supplied in packed form
.SH SYNOPSIS
.TP 14
REAL FUNCTION
SLANSP( NORM, UPLO, N, AP, WORK )
.TP 14
.ti +4
CHARACTER
NORM, UPLO
.TP 14
.ti +4
INTEGER
N
.TP 14
.ti +4
REAL
AP( * ), WORK( * )
.SH PURPOSE
SLANSP 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 symmetric matrix A, supplied in packed form.
.SH DESCRIPTION
SLANSP returns the value
.br
SLANSP = ( max(abs(A(i,j))), NORM = 'M' or 'm'
.br
(
.br
( norm1(A), NORM = '1', 'O' or 'o'
.br
(
.br
( normI(A), NORM = 'I' or 'i'
.br
(
.br
( 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 matrix norm.
.SH ARGUMENTS
.TP 8
NORM (input) CHARACTER*1
Specifies the value to be returned in SLANSP as described
above.
.TP 8
UPLO (input) CHARACTER*1
Specifies whether the upper or lower triangular part of the
symmetric matrix A is supplied.
= 'U': Upper triangular part of A is supplied
.br
= 'L': Lower triangular part of A is supplied
.TP 8
N (input) INTEGER
The order of the matrix A. N >= 0. When N = 0, SLANSP is
set to zero.
.TP 8
AP (input) REAL array, dimension (N*(N+1)/2)
The upper or lower triangle of the symmetric matrix A, packed
columnwise in a linear array. The j-th column of A is stored
in the array AP as follows:
if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.
.TP 8
WORK (workspace) REAL array, dimension (LWORK),
where LWORK >= N when NORM = 'I' or '1' or 'O'; otherwise,
WORK is not referenced.
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