Function dnrm2_subrow (o2scl_cblas)¶
-
template<class mat_t>
double o2scl_cblas::dnrm2_subrow(const mat_t &M, const size_t ir, const size_t ic, const size_t N)¶ Compute the norm of a subrow of a matrix.
Given the matrix
X
, define the vectorx
as the row with indexir
. This function computes the norm of the part ofx
from columnic
to column(inclusive). All other elements in
x
are not referenced.Note
The suffix “2” on the function name indicates that this computes the “2-norm”, not that the norm is squared.