dlanst (l) - Linux Manuals
dlanst: 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
Command to display dlanst manual in Linux: $ man l dlanst
NAME
DLANST - 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
SYNOPSIS
- DOUBLE PRECISION
-
FUNCTION DLANST( NORM, N, D, E )
-
CHARACTER
NORM
-
INTEGER
N
-
DOUBLE
PRECISION D( * ), E( * )
PURPOSE
DLANST 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.
DESCRIPTION
DLANST returns the value
DLANST
= ( 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 DLANST as described
above.
- N (input) INTEGER
-
The order of the matrix A. N >= 0. When N = 0, DLANST is
set to zero.
- D (input) DOUBLE PRECISION array, dimension (N)
-
The diagonal elements of A.
- E (input) DOUBLE PRECISION array, dimension (N-1)
-
The (n-1) sub-diagonal or super-diagonal elements of A.
Pages related to dlanst
- dlanst (3)
- dlansb (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
- dlansf (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
- dlansp (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
- dlansy (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
- dlaneg (l) - computes the Sturm count, the number of negative pivots encountered while factoring tridiagonal T - sigma I = L D L^T
- dlangb (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
- dlange (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
- dlangt (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
- dlanhs (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