def selectJ(i, oS, Ei):
maxK = -1
maxDeltaE = 0
Ej = 0
#set corresponding cached value as valid
oS.eCache[i] = [1,Ei]
#return the corresponding alpha of non-zero E
validEcacheList = nonzero(oS.eCache[:,0].A)[0]
#select the alpha j that maximum abs(Ei - Ek)
if(len(validEcacheList)) > 1:
for k in validEcacheList:
if k == i:
continue
Ek = calcEk(oS, k)
deltaE = abs(Ei - Ek)
if(deltaE > maxDeltaE):
maxK = k; maxDeltaE = deltaE; Ej = Ek
return maxK, Ej
#if there is no such j, random select a j
else:
j = smo.selectJrand(i, oS.m)
Ej = calcEk(oS,j)
return j, Ej
def selectJ(i, oS, Ei):
maxK = -1
maxDeltaE = 0
Ej = 0
#set corresponding cached value as valid
oS.eCache[i] = [1, Ei]
#return the corresponding alpha of non-zero E
validEcacheList = nonzero(oS.eCache[:, 0].A)[0]
#select the alpha j that maximum abs(Ei - Ek)
if (len(validEcacheList)) > 1:
for k in validEcacheList:
if k == i:
continue
Ek = calcEk(oS, k)
deltaE = abs(Ei - Ek)
if (deltaE > maxDeltaE):
maxK = k
maxDeltaE = deltaE
Ej = Ek
return maxK, Ej
#if there is no such j, random select a j
else:
j = smo.selectJrand(i, oS.m)
Ej = calcEk(oS, j)
return j, Ej
def selectJ(i, oS, Ei):
maxK = -1
maxDeltaE = 0
Ej = 0
oS.eCache[i] = [1, Ei] #eCahe是所有误差的缓存区
vaildEcacheList = nonzero(oS.eCache[:, 0].A)[0]
#.A表示转化为array,注意nonzero返回的成对的值,这里validEcache返回的是第一列非零的行索引.见博客:https://blog.csdn.net/qq_28773183/article/details/81013226
if (len(vaildEcacheList)) > 1:
for k in vaildEcacheList:
if k == i: continue
Ek = calcEk(oS, k) #计算Ek,有索引k即可
deltaE = abs(Ei - Ek)
if (deltaE > maxDeltaE):
maxK = k
maxDeltaE = deltaE
Ej = Ek
return maxK, Ej
else: #随机选择alphaJ
j = SMO.selectJrand(i, oS.m)
Ej = calcEk(oS, j)
return j, Ej
