Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
Drexel University or The Math Forum.



Re: Neural Network  Incremental Training
Posted:
Jun 5, 2014 11:41 PM


% I have studied the newrb algorithm, and my understanding of it is as follows: % % 1. an empty network is created % a. the weight, net input and transfer functions are defined % b. the architecture of the network is defined % c. the design of the network is invoked % 2. during the initial design stage % a. the radial basis layer outputs are calculated % b. the correlation coefficients between the network outputs and the target outputs are calculated % c. the sample with the most "error" is picked from P % d. the first neuron is being calculated from the picked sample and the network inputs
network 'parameters'
% e. MSE value between the target outputs and the calculated neuron outputs is calculated % f. the struct 'tr' is created, which holds the epochs and MSE values for each epoch (with this it % indicates the performance of the network) % 3. during the iterative stage of the design % a. number of iterations is the maximum number of neurons set earlier % b. again we calculate the correlation coefficients between the network outputs and the % target outputs % c. from the remainder of the network inputs we again pick the one with the most "error" % d. we calculate the next neuron from the picked sample and the network inputs % e. MSE value between the target outputs and the calculated neuron outputs is calculated % f. the struct 'tr' is expanded with new epochs and MSEs % g. if the current MSE is lower than the set goal, break the for loop and end training of % further neurons % 4. end of algorithm % a. the values of w1 (weights in the first layer), b1 (biases of the first layer), w2 (weights of % the second layer) and b2 (biases of the second layer) are outputs of the algorithm % b. tr is also an output, but it is not saved in the net object (while w1, b1, w2 and b2 are) % c. the network parameters are set to the outputs of the design stage % d. the network is initialized with these values % % Could you please tell me have I made an error somewhere in my understanding? % % I would also like to ask, which variables did you mean when you mentioned the Calibration Set?
Sorry, that was a way I kept MLPs from "forgetting". It is not applicable here.
% I would like to test and develop this algorithm on a XOR example, where I would first train a % RBFNN with 3 samples, initialize the network and save it and then load the same network % and add the 4. sample to it. Would this be wise, or should I try with a different starting example?
Standardize inputs and regression outputs to zeromean and unit variance Use 01 unit vector outputs for classifiers Define MSE00 = mean(var(t',1)) % average target variance A reasonable goal is MSEgoal = 0.01*MSE00 % R^2 = 0.99 Start with spread = 1 and change by powers of 2 until number of hidden nodes is minimized
net = newrb( x,t,MSEgoal,spread); Search for my examples
greg newrb
You can try your example and end up with 4 neurons because none of the 4 is 'like' the other 3
Then try the simple example in the documentation
help newrb
Then try the simple_cluster problem
help nndatasets
Hope this helps.
The main fault of this network is that you cannot define a set of initial clusters.
ope this helps.



