A finite set
N Ì \RdN \subset \R^d is a {\em weak
\eps\eps-net} for an
nn-point set
X Ì \RdX\subset \R^d (with respect to convex sets) if
NN
intersects every convex set
KK with
|K Ç X| ³ \eps n|K\,\cap\,X|\geq \eps n. We
give an alternative, and arguably simpler, proof of the fact, first
shown by Chazelle et al., that every
point set
XX in
\Rd\R^d admits a weak
\eps\eps-net of cardinality
O(\eps-d\polylog(1/\eps))O(\eps^{-d}\polylog(1/\eps)). Moreover, for a number of special
point sets (e.g., for points on the moment curve), our method gives
substantially better bounds. The construction
yields an algorithm to construct such weak
\eps\eps-nets in time
O(nln(1/\eps))O(n\ln(1/\eps)).