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我寫了Pybrain神經網絡的這個簡單測試,但它並沒有像我期望的那樣工作。這個想法是訓練一個數字集到4095的數據集,其中包含素數和非素數。神經網絡對不同的激活報告相同的響應
#!/usr/bin/env python
# A simple feedforward neural network that attempts to learn Primes
from pybrain.datasets import ClassificationDataSet
from pybrain.tools.shortcuts import buildNetwork
from pybrain.supervised import BackpropTrainer
class PrimesDataSet(ClassificationDataSet):
""" A dataset for primes """
def generatePrimes(self, n):
if n == 2:
return [2]
elif n < 2:
return []
s = range(3, n + 1, 2)
mroot = n ** 0.5
half = (n + 1)/2 - 1
i = 0
m = 3
while m <= mroot:
if s[i]:
j = (m * m - 3)/2
s[j] = 0
while j < half:
s[j] = 0
j += m
i = i + 1
m = 2 * i + 3
return [2] + [x for x in s if x]
def binaryString(self, n):
return "{0:12b}".format(n)
def __init__(self):
ClassificationDataSet.__init__(self, 12, 1)
primes = self.generatePrimes(4095)
for prime in primes:
b = self.binaryString(prime).split()
self.addSample(b, [1])
for n in range(4095):
if n not in primes:
b = self.binaryString(n).split()
self.addSample(b, [0])
def testTraining():
d = PrimesDataSet()
d._convertToOneOfMany()
n = buildNetwork(d.indim, 12, d.outdim, recurrent=True)
t = BackpropTrainer(n, learningrate = 0.01, momentum = 0.99, verbose = True)
t.trainOnDataset(d, 100)
t.testOnData(verbose=True)
print "Is 7 prime? ", n.activate(d.binaryString(7).split())
print "Is 6 prime? ", n.activate(d.binaryString(6).split())
print "Is 100 prime? ", n.activate(d.binaryString(100).split())
if __name__ == '__main__':
testTraining()
直索(請)這是否甚至有可能的問題,我的問題是,7,6,和100的最後三個報表打印測試是否是質都返回相同的:
Is 7 prime? [ 0.34435841 0.65564159]
Is 6 prime? [ 0.34435841 0.65564159]
Is 100 prime? [ 0.34435841 0.65564159]
(或類似的東西) 我解釋這些結果的方式是神經網絡以65%的確定性預測這些數字中的每一個是是質數。我的神經網絡學會了如何處理所有的輸入,或者我做錯了什麼?
謝謝!最簡單的事情 - 我甚至沒想過要檢查。 – lambda