支持向量機及python代碼實現(xiàn)-資料下載頁
2025-06-29 01:41本頁面
【正文】 268. defcalcEkK(oS,k):269. fXk=float(multiply(,).T*(*[k,:].T))+270. Ek=fXkfloat([k])271. returnEk272. 273. defselectJK(i,oS,Ei):thisisthesecondchoiceheurstic,andcalcsEj274. maxK=1。maxDeltaE=0。Ej=0275. [i]=[1,Ei]setvalidchoosethealphathatgivesthemaximumdeltaE276. validEcacheList=nonzero([:,0].A)[0]277. if(len(validEcacheList))1:278. forkinvalidEcacheList:loopthroughvalidEcachevaluesandfindtheonethatmaximizesdeltaE279. ifk==i:continuedon39。tcalcfori,wasteoftime280. Ek=calcEk(oS,k)281. deltaE=abs(EiEk)282. if(deltaEmaxDeltaE):283. maxK=k。maxDeltaE=deltaE。Ej=Ek284. returnmaxK,Ej285. else:inthiscase(firsttimearound)wedon39。thaveanyvalideCachevalues286. j=selectJrand(i,)287. Ej=calcEk(oS,j)288. returnj,Ej289. 290. defupdateEkK(oS,k):afteranyalphahaschangedupdatethenewvalueinthecache291. Ek=calcEk(oS,k)292. [k]=[1,Ek]293. 294. definnerLK(i,oS):295. Ei=calcEk(oS,i)296. if(([i]*Ei)and([i]))or(([i]*Ei)and([i]0)):297. j,Ej=selectJ(i,oS,Ei)thishasbeenchangedfromselectJrand298. alphaIold=[i].copy()。alphaJold=[j].copy()。299. if([i]!=[j]):300. L=max(0,[j][i])301. H=min(,+[j][i])302. else:303. L=max(0,[j]+[i])304. H=min(,[j]+[i])305. ifL==H:printL==H。return0306. eta=*[i,:]*[j,:].T[i,:]*[i,:].T[j,:]*[j,:].T307. ifeta=0:printeta=0。return0308. [j]=[j]*(EiEj)/eta309. [j]=clipAlpha([j],H,L)310. updateEk(oS,j)addedthisfortheEcache311. if(abs([j]alphaJold)):printjnotmovingenough。return0312. [i]+=[j]*[i]*(alphaJold[j])updateibythesameamountasj313. updateEk(oS,i)addedthisfortheEcachetheupdateisintheoppostiedirection314. b1=Ei[i]*([i]alphaIold)*[i,:]*[i,:].T[j]*([j]alphaJold)*[i,:]*[j,:].T315. b2=Ej[i]*([i]alphaIold)*[i,:]*[j,:].T[j]*([j]alphaJold)*[j,:]*[j,:].T316. if(0[i])and([i]):=b1317. elif(0[j])and([j]):=b2318. else:=(b1+b2)/319. return1320. else:return0321. 322. defsmoPK(dataMatIn,classLabels,C,toler,maxIter):fullPlattSMO323. oS=optStruct(mat(dataMatIn),mat(classLabels).transpose(),C,toler)324. iter=0325. entireSet=True。alphaPairsChanged=0326. while(itermaxIter)and((alphaPairsChanged0)or(entireSet)):327. alphaPairsChanged=0328. ifentireSet:gooverall329. foriinrange():330. alphaPairsChanged+=innerL(i,oS)331. printfullSet,iter:%di:%d,pairschanged%d%(iter,i,alphaPairsChanged)332. iter+=1333. else:goovernonbound(railed)alphas334. nonBoundIs=nonzero((0)*(C))[0]335. foriinnonBoundIs:336. alphaPairsChanged+=innerL(i,oS)337. printnonbound,iter:%di:%d,pairschanged%d%(iter,i,alphaPairsChanged)338. iter+=1339. ifentireSet:entireSet=Falsetoggleentiresetloop340. elif(alphaPairsChanged==0):entireSet=True341. printiterationnumber:%d%iter342. return,運行結(jié)果如（圖八）所示：（圖八）參考文獻： [1]machine learning in action. PeterHarrington [2] pattern recognition and machinelearning. Christopher M. Bishop [3]machine Ng
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