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SLANSP(1) LAPACK auxiliary routine (version 3.2) SLANSP(1)

NAME

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

SYNOPSIS

SLANSP( NORM, UPLO, N, AP, WORK )

CHARACTER NORM, UPLO INTEGER N REAL AP( * ), WORK( * )

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.

DESCRIPTION

SLANSP returns the value
SLANSP = ( 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.

ARGUMENTS

Specifies the value to be returned in SLANSP as described above.
Specifies whether the upper or lower triangular part of the symmetric matrix A is supplied. = 'U': Upper triangular part of A is supplied
= 'L': Lower triangular part of A is supplied
The order of the matrix A. N >= 0. When N = 0, SLANSP is set to zero.
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.
where LWORK >= N when NORM = 'I' or '1' or 'O'; otherwise, WORK is not referenced.
November 2008 LAPACK auxiliary routine (version 3.2)