import numpy as np
import scipy.special
import copy
class MLPNet:
def __init__(self, hiddenlayer=(10,10),classification=False):
self.hl = hiddenlayer; self.classification = classification
self.xMin = 0.0; self.xMax = 1.0
self.W = []
self._sigmoid = lambda x: scipy.special.expit(x)
def _initWeights(self):
self.W.append((np.random.rand(self.hl[0],self.il) - 0.5 ))
self.W.append((np.random.rand(self.hl[1],self.hl[0]) - 0.5))
self.W.append((np.random.rand(self.ol,self.hl[1]) - 0.5))
def _calOut(self,X):
O1 = self._sigmoid(self.W[0]@X.T)
O2 = self._sigmoid(self.W[1]@O1)
y = (self.W[len(self.W)-1]@O2).T
return(y)
def predict(self,X):
X = (X - self.xMin) / (self.xMax - self.xMin)
X = np.hstack( (X,np.ones(X.shape[0])[:,None]) )
y = self._calOut(X)
if self.classification: y = np.round(y) #*\label{code:fullmlpbatch:1}
return(y)
def fit(self,X,Y,eta=0.75,maxIter=200,vareps=10**-3,scale=True,XT=None,YT=None): #*\label{code:fullmlpbatch:4}
self.xMin = X.min(axis=0) if scale else 0
self.xMax = X.max(axis=0) if scale else 1
X = (X - self.xMin) / (self.xMax - self.xMin)
X = np.hstack( (X,np.ones(X.shape[0])[:,None]) )
if len(Y.shape) == 1:
Y = Y[:,None]
self.il = X.shape[1]
self.ol = Y.shape[1] #*\label{code:fullmlpbatch:morethanone}
self._initWeights()
(XVal, YVal, X, Y) = self._divValTrainSet(X,Y) #*\label{code:fullmlpbatch:3}
self.train(X,Y,XVal,YVal,eta,maxIter,vareps,XT,YT)
def train(self,X,Y,XVal=None,YVal=None,eta=0.75,maxIter=200,vareps=10**-3,XT=None,YT=None):
if XVal is None: (XVal, YVal, X, Y) = self._divValTrainSet(X,Y)
if len(Y.shape) == 1: Y = Y[:,None]
if len(YVal.shape) == 1: YVal = YVal[:,None]
if self.il != X.shape[1]: X = np.hstack( (X,np.ones(X.shape[0])[:,None]) )
if self.il != XVal.shape[1]: XVal = np.hstack( (XVal,np.ones(XVal.shape[0])[:,None]) )
dW = []
for i in range(len(self.W)):
dW.append(np.zeros_like(self.W[i]))
yp = self._calOut(XVal)
if self.classification: yp = np.round(yp)
meanE = (np.sum((YVal-yp)**2)/XVal.shape[0])/YVal.shape[1]
minError = meanE
minW = copy.deepcopy(self.W)
self.errorVal=[]; self.errorTrain=[]; self.errorTest=[] #*\label{code:fullmlpbatch:2}
mixSet = np.random.choice(X.shape[0],X.shape[0],replace=False)
counter = 0
while meanE > vareps and counter < maxIter:
counter += 1
for m in range(self.ol): #*\label{code:fullmlpbatch:5}
for i in mixSet:
x = X[i,:]
O1 = self._sigmoid(self.W[0]@x.T)
O2 = self._sigmoid(self.W[1]@O1)
temp = self.W[2][m,:]*O2*(1-O2)[None,:]
dW[2] = O2
dW[1] = temp.T@O1[:,None].T
dW[0] = (O1*(1-O1)*([email protected][1])).T@x[:,None].T
yp = self._calOut(x)[m]
yfactor = np.sum(Y[i,m]-yp)
for j in range(len(self.W)):
self.W[j] += eta * yfactor* dW[j]
yp = self._calOut(XVal)
if self.classification: yp = np.round(yp)
meanE = (np.sum((YVal-yp)**2)/XVal.shape[0])/YVal.shape[1] #*\label{code:fullmlpbatch:6}
self.errorVal.append(meanE)
if meanE < minError:
minError = meanE
minW = copy.deepcopy(self.W)
self.valChoise = counter
if XT is not None:
yp = self.predict(XT)
if len(YT.shape) == 1: YT = YT[:,None];
meanETest = (np.sum((YT-yp)**2)/XT.shape[0])/YT.shape[1]
self.errorTest.append(meanETest)
yp = self._calOut(X)
if self.classification:
yp = np.round(yp)
meanETrain = (np.sum((Y-yp)**2)/X.shape[0])/Y.shape[1]
self.errorTrain.append(meanETrain)
self.W = copy.deepcopy(minW)
def _divValTrainSet(self, X,Y):
self.ValSet = np.random.choice(X.shape[0],int(X.shape[0]*0.25),replace=False)
self.TrainSet = np.delete(np.arange(0, Y.shape[0] ), self.ValSet)
XVal = X[self.ValSet,:]
YVal = Y[self.ValSet]
X = X[self.TrainSet,:]
Y = Y[self.TrainSet]
return (XVal, YVal, X, Y)
def exportNet(self, filePrefix):
np.savetxt(filePrefix+"MinMax.csv", np.array([self.xMin, self.xMax]), delimiter=",")
np.savetxt(filePrefix+"W0.csv", self.W[0], delimiter=",")
np.savetxt(filePrefix+"W1.csv", self.W[1], delimiter=",")
np.savetxt(filePrefix+"W2.csv", self.W[2], delimiter=",")
def importNet(self,filePrefix, classification=False):
MinMax = np.loadtxt(filePrefix+'MinMax.csv',delimiter=",")
W2 = np.loadtxt(filePrefix+'W2.csv',delimiter=",")
W1 = np.loadtxt(filePrefix+'W1.csv',delimiter=",")
W0 = np.loadtxt(filePrefix+'W0.csv',delimiter=",")
self.W = [W0,W1,W2]
self.hl = (W0.shape[0], W2.shape[1])
self.il = W0.shape[1]
self.ol = W2.shape[0]
self.xMin = MinMax[0]
self.xMax = MinMax[1]
self.classification = classification
if __name__ == '__main__':
np.random.seed(42)
X = np.random.rand(1250,2)
Y = np.zeros( (1250,2) )
index1 = (X[:,0] - 0.25)**2 + (X[:,1] - 0.25)**2 < 0.2**2
Y[index1,0] = 1
index2 = (X[:,0] - 0.75)**2 + (X[:,1] - 0.75)**2 < 0.2**2
Y[index2,1] = 1
TrainSet = np.random.choice(X.shape[0],int(X.shape[0]*0.70), replace=False)
XTrain = X[TrainSet,:]
YTrain = Y[TrainSet]
TestSet = np.delete(np.arange(0, len(Y) ), TrainSet)
XTest = X[TestSet,:]
YTest = Y[TestSet]
myPredict = MLPNet(hiddenlayer=(24,24),classification=True)
myPredict.fit(XTrain,YTrain,maxIter=1200, XT=XTest , YT=YTest)
yp = myPredict.predict(XTest)
fp = np.sum(np.abs(yp - YTest))/len(TestSet)*100
print('richtig klassifiziert %0.1f%%' % (100-fp))
print('falsch klassifiziert %0.1f%%' % (fp))
myPredict.exportNet('foobar')
justTest = MLPNet()
justTest.importNet('foobar',classification=True)
yp = justTest.predict(XTest)
fp = np.sum(np.abs(yp - YTest))/len(TestSet)*100
print('richtig klassifiziert %0.1f%%' % (100-fp))
print('falsch klassifiziert %0.1f%%' % (fp))
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
from matplotlib import cm
plt.close('all')
fig1 = plt.figure(1)
ax = fig1.add_subplot(1,1,1)
circle1 = plt.Circle((0.25, 0.25), 0.2, color='k', alpha=0.3)
circle2 = plt.Circle((0.75, 0.75), 0.2, color='k', alpha=0.3)
ax.add_artist(circle1)
ax.add_artist(circle2)
index1 = np.logical_and( (XTest[:,0] - 0.25)**2 + (XTest[:,1] - 0.25)**2 < 0.2**2 , yp[: ,0]==0 )
ax.scatter(XTest[index1,0],XTest[index1,1], marker='v',c='r')
index2 = np.logical_and( (XTest[:,0] - 0.75)**2 + (XTest[:,1] - 0.75)**2 < 0.2**2, yp[: ,1]==0 )
ax.scatter(XTest[index2,0],XTest[index2,1], marker='^',c='r')
ax.scatter(XTest[yp[:,0]==1,0],XTest[yp[:,0]==1,1], marker='+',c='k')
ax.scatter(XTest[yp[:,1]==1,0],XTest[yp[:,1]==1,1], marker='o',c='k')
ax.set_xlabel('$x_0$')
ax.set_ylabel('$x_1$')
ax.set_xlim(0,1)
ax.set_ylim(0,1)
ax.axis('equal')
fig3 = plt.figure(3)
ax = fig3.add_subplot(1,1,1)
epochen = np.arange(len(myPredict.errorVal))
ax.plot(epochen, np.array(myPredict.errorVal), 'r-.' , label='Validierung')
ax.plot(epochen, np.array(myPredict.errorTest), 'k--', label='Test')
ax.plot(epochen, np.array(myPredict.errorTrain), 'k:', label='Training' )
ax.legend()
ax.set_xlabel('Lernzyklus')
ax.set_ylabel('Durchschnittlicher Fehler')
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