slantr (l) - Linux Manuals
slantr: returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a trapezoidal or triangular matrix A
NAME
SLANTR - returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a trapezoidal or triangular matrix ASYNOPSIS
- REAL FUNCTION
- SLANTR( NORM, UPLO, DIAG, M, N, A, LDA, WORK )
- CHARACTER DIAG, NORM, UPLO
- INTEGER LDA, M, N
- REAL A( LDA, * ), WORK( * )
PURPOSE
SLANTR returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a trapezoidal or triangular matrix A.DESCRIPTION
SLANTR returns the valueSLANTR
ARGUMENTS
- NORM (input) CHARACTER*1
- Specifies the value to be returned in SLANTR as described above.
- UPLO (input) CHARACTER*1
-
Specifies whether the matrix A is upper or lower trapezoidal.
= aqUaq: Upper trapezoidal
= aqLaq: Lower trapezoidal Note that A is triangular instead of trapezoidal if M = N. - DIAG (input) CHARACTER*1
-
Specifies whether or not the matrix A has unit diagonal.
= aqNaq: Non-unit diagonal
= aqUaq: Unit diagonal - M (input) INTEGER
- The number of rows of the matrix A. M >= 0, and if UPLO = aqUaq, M <= N. When M = 0, SLANTR is set to zero.
- N (input) INTEGER
- The number of columns of the matrix A. N >= 0, and if UPLO = aqLaq, N <= M. When N = 0, SLANTR is set to zero.
- A (input) REAL array, dimension (LDA,N)
- The trapezoidal matrix A (A is triangular if M = N). If UPLO = aqUaq, the leading m by n upper trapezoidal part of the array A contains the upper trapezoidal matrix, and the strictly lower triangular part of A is not referenced. If UPLO = aqLaq, the leading m by n lower trapezoidal part of the array A contains the lower trapezoidal matrix, and the strictly upper triangular part of A is not referenced. Note that when DIAG = aqUaq, the diagonal elements of A are not referenced and are assumed to be one.
- LDA (input) INTEGER
- The leading dimension of the array A. LDA >= max(M,1).
- WORK (workspace) REAL array, dimension (MAX(1,LWORK)),
-
where LWORK >= M when NORM = aqIaq; otherwise, WORK is not
referenced.