607.txt

This complete matlab for neural network

发信人: daniel (飞翔鸟), 信区: DataMining
标  题: Re: 有些迷惑
发信站: 南京大学小百合站 (Mon Dec 30 12:23:29 2002)


【 在 adson (自强乃报国之本) 的大作中提到: 】
: excuse me, what is NFL?

NFL just means you get some goodness but sacrifice others. It should 
not be anticipated to get something good in every aspect or in every 
way. This idea is not new. Even in 1980s', researchers have implicitly 
regarded it as a norm. But until D. Wolpert, it has not been rigorously 
justified. So, at present NFL theorem is regarded as the achievement 
of him. It is worth noting that NFL does not conflict ML research because
NFL just states that there is no universal winner, which is obvious
correct. But for specific scenarios, there may exist a winner.

for NFL, refer: 
D.H. Wolpert and W.G. Macready. No free lunch theorems for optimization. 
IEEE TEC97, 1(1)
M. Koppen, D.H. Wolpert, and W.G. Macready. Remarks on a recent paper
on the no free lunch theorems. IEEE TEC01, 5(3)

: 
: 【 在 ihappy 的大作中提到: 】
: : hehe, from the perspective of data mining, such tricks are important.
: : but there is the NFL theorem. In fact, i think before study any specific
: : ML algorithm, NFL should be mentioned first.
: : 【 在 GzLi (笑梨) 的大作中提到: 】


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