HPL_dlange(3) HPL Library Functions HPL_dlange(3) NAME HPL_dlange - Compute ||A||. SYNOPSIS #include "hpl.h" double HPL_dlange( const HPL_T_NORM NORM, const int M, const int N, const double * A, const int LDA ); DESCRIPTION HPL_dlange returns the value of the one norm, or the infinity norm, or the element of largest absolute value of a matrix A: max(abs(A(i,j))) when NORM = HPL_NORM_A, norm1(A), when NORM = HPL_NORM_1, normI(A), when NORM = HPL_NORM_I, where norm1 denotes the one norm of a matrix (maximum column sum) and normI denotes the infinity norm of a matrix (maximum row sum). Note that max(abs(A(i,j))) is not a matrix norm. ARGUMENTS NORM (local input) const HPL_T_NORM On entry, NORM specifies the value to be returned by this func- tion as described above. M (local input) const int On entry, M specifies the number of rows of the matrix A. M must be at least zero. N (local input) const int On entry, N specifies the number of columns of the matrix A. N must be at least zero. A (local input) const double * On entry, A points to an array of dimension (LDA,N), that con- tains the matrix A. LDA (local input) const int On entry, LDA specifies the leading dimension of the array A. LDA must be at least max(1,M). EXAMPLE #include "hpl.h" int main(int argc, char *argv[]) { double a[2*2]; a[0] = 1.0; a[1] = 3.0; a[2] = 2.0; a[3] = 4.0; norm = HPL_dlange( HPL_NORM_I, 2, 2, a, 2 ); printf("norm=%f\n", norm); exit(0); return(0); } SEE ALSO HPL_dlaprnt (3), HPL_fprintf (3). HPL 2.3 December 2, 2018 HPL_dlange(3)
NAME | SYNOPSIS | DESCRIPTION | ARGUMENTS | EXAMPLE | SEE ALSO
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