from?scipy?import?*
from?scipy.linalg?import?normpinv

from?matplotlib?import?pyplot?as?plt

class?RBF:
????def?__init__（selfindimnumCentersoutdim）:
????????self.indim?=?indim
????????self.outdim?=?outdim
????????self.numCenters?=?numCenters
????????self.centers?=?[random.uniform（-11indim）?for?i?in?range（numCenters）]
????????self.beta?=?8
????????self.W?=?random.random（（self.numCentersself.outdim））

????def?_basisfunc（selfcd）:
????????assert?len（d）?==?self.indim
????????return?exp（-self.beta*norm（c-d）**2）

????def?_calcAct（self?X）:
????????#?calculate?activations?of?RBFs

????????G?=?zeros（（X.shape[0]?self.numCenters）?float）
????????for?ci?c?in?enumerate（self.centers）:
????????????for?xi?x?in?enumerate（X）:
????????????????G[xi?ci]?=?self._basisfunc（c?x）
????????return?G

????def?train（self?X?Y）:

????????“““?X:?matrix?of?dimensions?n?x?indim
????????????y:?column?vector?of?dimension?n?x?1?“““
????????#?choose?random?center?vectors?from?training?set

????????rnd_idx?=?random.permutation（X.shape[0]）[:self.numCenters]
????????self.centers?=?[X[i?:]?for?i?in?rnd_idx]
????????print
????????“center“?