Visible to Intel only — GUID: GUID-7D91F874-822D-409C-A430-5118FF797251
Visible to Intel only — GUID: GUID-7D91F874-822D-409C-A430-5118FF797251
?lansf
Returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a symmetric matrix in RFP format.
Syntax
val = slansf(norm, transr, uplo, n, a, work)
val = dlansf(norm, transr, uplo, n, a, work)
Include Files
- mkl.fi
Description
T
The function ?lansf returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of an n-by-n real symmetric matrix A in the rectangular full packed (RFP) format .
Input Parameters
- 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).
- transr
-
CHARACTER*1.
Specifies whether the RFP format of matrix A is normal or transposed format.
If transr = 'N': RFP format is normal;
if transr = 'T': RFP format is transposed.
- uplo
-
CHARACTER*1.
Specifies whether the RFP matrix A came from upper or lower triangular matrix.
If uplo = 'U': RFP matrix A came from an upper triangular matrix;
if uplo = 'L': RFP matrix A came from a lower triangular matrix.
- n
-
INTEGER. The order of the matrix A. n≥ 0.
When n = 0, ?lansf is set to zero.
- a
-
REAL for slansf
DOUBLE PRECISION for dlansf
Array, DIMENSION (n*(n+1)/2).
The upper (if uplo = 'U') or lower (if uplo = 'L') part of the symetric matrix A stored in RFP format.
- work
-
REAL for slansf.
DOUBLE PRECISION for dlansf.
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 slansf
DOUBLE PRECISION for dlansf
Value returned by the function.