Visible to Intel only — GUID: GUID-51833F97-8313-49E2-A677-D3EED41D49C9
Visible to Intel only — GUID: GUID-51833F97-8313-49E2-A677-D3EED41D49C9
?lansy
Returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a real/complex symmetric matrix.
Syntax
val = slansy( norm, uplo, n, a, lda, work )
val = dlansy( norm, uplo, n, a, lda, work )
val = clansy( norm, uplo, n, a, lda, work )
val = zlansy( norm, uplo, n, a, lda, work )
Include Files
- mkl.fi
Description
The function ?lansy returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a real/complex symmetric matrix A.
Input Parameters
The data types are given for the Fortran interface.
- norm
-
CHARACTER*1. Specifies the value to be returned by the routine:
= 'M' or 'm': val = max(abs(Aij)), largest absolute value of the matrix A.
= '1' or 'O' or 'o': val = norm1(A), 1-norm of the matrix A (maximum column sum),
= 'I' or 'i': val = normI(A), infinity norm of the matrix A (maximum row sum),
= 'F', 'f', 'E' or 'e': val = normF(A), Frobenius norm of the matrix A (square root of sum of squares).
- uplo
-
CHARACTER*1.
Specifies whether the upper or lower triangular part of the symmetric matrix A is to be referenced.
= 'U': Upper triangular part of A is referenced.
= 'L': Lower triangular part of A is referenced
- n
-
INTEGER. The order of the matrix A. n≥ 0. When n = 0, ?lansy is set to zero.
- a
-
REAL for slansy
DOUBLE PRECISION for dlansy
COMPLEX for clansy
DOUBLE COMPLEX for zlansy
Array, size (lda,n). The symmetric matrix A.
If uplo = 'U', 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 = 'L', 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
-
INTEGER. The leading dimension of the array a.
lda≥ max(n,1).
- work
-
REAL for slansy and clansy.
DOUBLE PRECISION for dlansy and zlansy.
Workspace array, DIMENSION(max(1,lwork)), where
lwork≥n when norm = 'I' or '1' or 'O'; otherwise, work is not referenced.
Output Parameters
- val
-
REAL for slansy/clansy
DOUBLE PRECISION for dlansy/zlansy
Value returned by the function.