Developer Reference for Intel® oneAPI Math Kernel Library for C

ID 766684
Date 11/07/2023
Public

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?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

float LAPACKE_slange (int matrix_layout, char norm, lapack_int m, lapack_int n, const float * a, lapack_int lda);

double LAPACKE_dlange (int matrix_layout, char norm, lapack_int m, lapack_int n, const double * a, lapack_int lda);

float LAPACKE_clange (int matrix_layout, char norm, lapack_int m, lapack_int n, const lapack_complex_float * a, lapack_int lda);

double LAPACKE_zlange (int matrix_layout, char norm, lapack_int m, lapack_int n, const lapack_complex_double * a, lapack_int lda);

Include Files

  • mkl.h

Description

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

A <datatype> placeholder, if present, is used for the C interface data types in the C interface section above. See C Interface Conventions for the C interface principal conventions and type definitions.

norm

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).

m

The number of rows of the matrix A.

m 0. When m = 0, ?lange is set to zero.

n

The number of columns of the matrix A.

n 0. When n = 0, ?lange is set to zero.

a

Array, size at least max(1, lda*n) for column major and max(1, lda*m) for row major layout. Array a contains the m-by-n matrix A.

lda

The leading dimension of the array a.

lda max(n,1) for column major layout and max(1,n) for row major layout.