slansy (l) - Linux Manuals
slansy: 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
Command to display slansy
manual in Linux: $ man l slansy
NAME
SLANSY - 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
SYNOPSIS
- REAL FUNCTION
-
SLANSY( NORM, UPLO, N, A, LDA, WORK )
-
CHARACTER
NORM, UPLO
-
INTEGER
LDA, N
-
REAL
A( LDA, * ), WORK( * )
PURPOSE
SLANSY 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.
DESCRIPTION
SLANSY returns the value
SLANSY
= ( max(abs(A(i,j))), NORM = aqMaq or aqmaq
(
( norm1(A), NORM = aq1aq, aqOaq or aqoaq
(
( normI(A), NORM = aqIaq or aqiaq
(
( normF(A), NORM = aqFaq, aqfaq, aqEaq or aqeaq
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
- NORM (input) CHARACTER*1
-
Specifies the value to be returned in SLANSY as described
above.
- UPLO (input) CHARACTER*1
-
Specifies whether the upper or lower triangular part of the
symmetric matrix A is to be referenced.
= aqUaq: Upper triangular part of A is referenced
= aqLaq: Lower triangular part of A is referenced
- N (input) INTEGER
-
The order of the matrix A. N >= 0. When N = 0, SLANSY is
set to zero.
- A (input) REAL array, dimension (LDA,N)
-
The symmetric matrix A. If UPLO = aqUaq, the leading n by n
upper triangular part of A contains the upper triangular part
of the matrix A, and the strictly lower triangular part of A
is not referenced. If UPLO = aqLaq, the leading n by n lower
triangular part of A contains the lower triangular part of
the matrix A, and the strictly upper triangular part of A is
not referenced.
- LDA (input) INTEGER
-
The leading dimension of the array A. LDA >= max(N,1).
- WORK (workspace) REAL array, dimension (MAX(1,LWORK)),
-
where LWORK >= N when NORM = aqIaq or aq1aq or aqOaq; otherwise,
WORK is not referenced.
Pages related to slansy
- slansy (3)
- slansb (l) - returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of an n by n symmetric band matrix A, with k super-diagonals
- slansf (l) - 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 in RFP format
- slansp (l) - 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
- slanst (l) - 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 tridiagonal matrix A
- slaneg (l) - computes the Sturm count, the number of negative pivots encountered while factoring tridiagonal T - sigma I = L D L^T
- slangb (l) - returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of an n by n band matrix A, with kl sub-diagonals and ku super-diagonals
- slange (l) - 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
- slangt (l) - 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 tridiagonal matrix A
- slanhs (l) - returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a Hessenberg matrix A