Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
?lange
Returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general rectangular matrix.
Syntax
valslange ( norm , m , n , a , lda , work )
valdlange ( norm , m , n , a , lda , work )
valclange ( norm , m , n , a , lda , work )
valzlange ( norm , m , n , a , lda , work )
Include Files
mkl.fi
Description
slange dlange clange zlange
The function ?lange 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 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(A_{ij})) , 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).
m
INTEGER . The number of rows of the matrix A .
m≥ 0 . When m = 0 , ?lange is set to zero.
n
INTEGER . The number of columns of the matrix A .
n≥ 0 . When n = 0 , ?lange is set to zero.
- a
-
REAL for slange DOUBLE PRECISION for dlange COMPLEX for clange DOUBLE COMPLEX for zlange Array, DIMENSION ( lda , n ).
Array a contains the m -by- n matrix A .
lda
INTEGER . The leading dimension of the array a .
.
- work
-
REAL for slange and clange . DOUBLE PRECISION for dlange and zlange . Workspace array, DIMENSION max(1,lwork) , where lwork≥m when norm = 'I' ; otherwise, work is not referenced.
Output Parameters
- val
-
REAL for slange / clange DOUBLE PRECISION for dlange / zlange Value returned by the function.