维基百科中的解释如下,请问那位知道比较形象化,直观一点的解释?
http://en.wikipedia.org/wiki/Weighting_Function
A weight function is a mathematical device used when performing a sum, integral, or average in order to give some elements more of a "weight" than others. They occur frequently in statistics and analysis, and are closely related to the concept of a measure. Weight functions can be constructed in both discrete and continuous settings.