Python Pybrain:运行时错误

我正试图用pybrain创建一个神经网络。 下面是我的代码

输入神经元的数量将是2500个。 输出神经元数为212个。 隐藏神经元数为（2500+212）/2=1356

我的代码：

#for training using the data set
#import built in json module for reading the binary list of lists
import json

#retrieve the input file
f = open('input.txt', 'r')
inputSet = json.load(f) 

#retrieve target file target file
f = open('target.txt', 'r')
targetSet = json.load(f)

#Width and height of character image
w,h = 50, 50

#import pybrain modules
from pybrain.structure.networks import FeedForwardNetwork
from pybrain.datasets import SupervisedDataSet
from pybrain.utilities import percentError
from pybrain.tools.shortcuts import buildNetwork
from pybrain.supervised.trainers import BackpropTrainer
from pybrain.structure.modules import SoftmaxLayer
from pybrain.structure.modules import LinearLayer
from pybrain.structure.modules import SigmoidLayer
from pybrain.structure.modules import TanhLayer
from pybrain.structure.connections import FullConnection
from pybrain.tools.customxml.networkwriter import NetworkWriter
from pybrain.tools.customxml.networkreader import NetworkReader

#import matplotlib to plot the learning graph
import matplotlib.pyplot as plt

#setting up the network
#initialize the number of neurons for the various layers
inputNeurons = w * h #2500
outputNeurons = 212
hiddenNeurons = int((inputNeurons + outputNeurons) /2) #1356

net = buildNetwork(inputNeurons, hiddenNeurons, outputNeurons, bias = True, hiddenclass = SigmoidLayer)

#view a glimpse of NN structure
print net

#initialise dataset
ds = SupervisedDataSet(inputNeurons, outputNeurons)

#add training data to network
for i in range(0,212):
    ds.addSample(inputSet[i], targetSet[i])

#print len(ds)

#initialize trainers
trainer = BackpropTrainer(net, dataset=ds,  learningrate = 0.01, momentum = 0.5, verbose=True)

#startTraining
trainer.trainEpochs (100)

#store network in XML
NetworkWriter.writeToFile(net, 'trained.xml')

问题是，对于除0.9以外的每个动量值，我都会遇到以下错误

Warning (from warnings module):
  File "C:\Python27\lib\site-packages\pybrain-0.3.1-py2.7.egg\pybrain\supervised\trainers\backprop.py", line 97
    error += 0.5 * sum(outerr ** 2)
RuntimeWarning: overflow encountered in square

Warning (from warnings module):
  File "C:\Python27\lib\site-packages\pybrain-0.3.1-py2.7.egg\pybrain\structure\modules\sigmoidlayer.py", line 14
    inerr[:] = outbuf * (1 - outbuf) * outerr
RuntimeWarning: invalid value encountered in multiply

我到处找了很多，但找不到具体的解决办法

我可以看出它与numpy有关，它不能处理大的浮点数，但我真的不知道如何去修复它

欢迎提出任何建议