Visible to Intel only — GUID: GUID-BE04762F-AC80-4CD2-A76A-24F80971712A
Visible to Intel only — GUID: GUID-BE04762F-AC80-4CD2-A76A-24F80971712A
?lansp
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 supplied in packed form.
Syntax
val = slansp( norm, uplo, n, ap, work )
val = dlansp( norm, uplo, n, ap, work )
val = clansp( norm, uplo, n, ap, work )
val = zlansp( norm, uplo, n, ap, work )
Include Files
- mkl.fi
Description
The function ?lansp 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, supplied in packed form.
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).
- uplo
-
CHARACTER*1.
Specifies whether the upper or lower triangular part of the symmetric matrix A is supplied.
If uplo = 'U': Upper triangular part of A is supplied
If uplo = 'L': Lower triangular part of A is supplied.
- n
-
INTEGER. The order of the matrix A. n≥ 0. When
n = 0, ?lansp is set to zero.
- ap
-
REAL for slansp
DOUBLE PRECISION for dlansp
COMPLEX for clansp
DOUBLE COMPLEX for zlansp
Array, DIMENSION (n(n+1)/2).
The upper or lower triangle of the symmetric matrix A, packed columnwise in a linear array. The j-th column of A is stored in the array ap as follows:
if uplo = 'U', ap(i + (j-1)j/2) = A(i,j) for 1 ≤ i ≤ j;
if uplo = 'L', ap(i + (j-1)(2n-j)/2) = A(i,j) for j ≤ i ≤ n.
- work
-
REAL for slansp and clansp.
DOUBLE PRECISION for dlansp and zlansp.
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 slansp/clansp
DOUBLE PRECISION for dlansp/zlansp
Value returned by the function.