For a subspace $X$ of functions from $L_2$ we consider the minimal number $m$ of nodes necessary for the exact discretization of the $L_2$-norm of the functions in $X$. We construct a subspace such that for any exact discretization with $m$ nodes there is at least one negative weight.
翻译:对于以2美元计的子空间功能的X美元,我们认为,在以X美元计的函数中,精确分解2美元以内,至少需要1百万美元的节点。 我们建造一个子空间,这样,在以1美元计的任何精确分解的节点上,至少有1个负重。