问题
I created a neural network matlab. This is the script:
load dati.mat; inputs=dati(:,1:8)'; targets=dati(:,9)'; hiddenLayerSize = 10; net = patternnet(hiddenLayerSize); net.inputs{1}.processFcns = {'removeconstantrows','mapminmax', 'mapstd','processpca'}; net.outputs{2}.processFcns = {'removeconstantrows','mapminmax', 'mapstd','processpca'}; net = struct(net); net.inputs{1}.processParams{2}.ymin = 0; net.inputs{1}.processParams{4}.maxfrac = 0.02; net.outputs{2}.processParams{4}.maxfrac = 0.02; net.outputs{2}.processParams{2}.ymin = 0; net = network(net); net.divideFcn = 'divideind'; net.divideMode = 'sample'; % Divide up every sample net.divideParam.trainInd = 1:428; net.divideParam.valInd = 429:520; net.divideParam.testInd = 521:612; net.trainFcn = 'trainscg'; % Scaled conjugate gradient backpropagation net.performFcn = 'mse'; % Mean squared error net.plotFcns = {'plotperform','plottrainstate','ploterrhist', 'plotregression', 'plotconfusion', 'plotroc'}; net=init(net); net.trainParam.max_fail=20; [net,tr] = train(net,inputs,targets); outputs = net(inputs); errors = gsubtract(targets,outputs); performance = perform(net,targets,outputs)
Now I want to save the weights and biases of the network and write the equation. I had saved the weights and biases:
W1=net.IW{1,1}; W2=net.LW{2,1}; b1=net.b{1,1}; b2=net.b{2,1};
So, I've done the data preprocessing and I wrote the following equation
max_range=0; [y,ps]=removeconstantrows(input, max_range); ymin=0; ymax=1; [y,ps2]=mapminmax(y,ymin,ymax); ymean=0; ystd=1; y=mapstd(x,ymean,ystd); maxfrac=0.02; y=processpca(y,maxfrac); in=y'; uscita=tansig(W2*(tansig(W1*in+b1))+b2);
But with the same input input=[1:8] I get different results. why? What's wrong? Help me please! It's important!
I use Matlab R2010B
回答1:
It looks like you are pre-processing the inputs but not post-processing the outputs. Post processing uses the "reverse" processing form. (Targets are pre-processed, so outputs are reverse processed).
回答2:
This equation
uscita=tansig(W2*(tansig(W1*in+b1))+b2);
is wrong. Why do you write two tansig
? You have 10 nerouns you should write it 10 times or use for i=1:10
;
来源:https://stackoverflow.com/questions/8837600/equation-that-compute-a-neural-network-in-matlab