Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
?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
valslansf ( norm , transr , uplo , n , a , work )
valdlansf ( norm , transr , uplo , n , a , work )
Include Files
mkl.fi
Description
slansf dlansf lansf 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.