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Greg Heath


3.065 total contributions since 2011

Backgound in Electromagnetic Theory, Plasma Physics and Radar Target Identification using Neural Networks.
PhD Student, Research Assistant and Lecturer at Stanford;
AB, ScB, ScM Student; Research Assistant, Fellow and Professor at Brown;
27 yrs researching Ballistic and Theatre Missile Defense using Neural Networks at MIT Lincoln Laboratory. Retired 2003.

PLEASE DO NOT SEND QUESTIONS AND DATA TO MY EMAIL. HOWEVER, CAN SEND LINKS TO POSTS.
Professional Interests: Neural Netwoks, Spectral Analysis

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Answered
Why my network is not giving the desired output
Design(training+validation), test and new data should all have the same summary statistics BEFORE NORMALIZATION. This may requir...

ein Tag ago | 0

| accepted

Answered
How to predict future responses y(t + 1) from the training of a narxnet network with past data of x (t) and y (t)? (NARXNET)
YOU DO NOT HAVE X and Y !!! YOU HAVE X and T where T = Ydesired Hope this helps Thank you for formally accepting m...

7 Tage ago | 1

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Answered
Testing a Backpropagation Neural Network
You are probably OVERTRAINING AN OVERFIT NET OVERFITTING: Using more unknown hidden nodes than number ...

9 Tage ago | 0

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Answered
The performance of hidden neurons
I think I misinterpreted the question. Now I think you mean when I increase the number of hidden nodes from 4 to 5 why do I star...

9 Tage ago | 0

Answered
Crossentropy loss function - What is a good performance goal?
These equations are not necessarily precise. For example: data = design + test design = training + validation In partic...

12 Tage ago | 0

Answered
How can two neural networks be compared for regression based on training and testing results ?
The MATLAB default is training/validation/testing fractions of 0.7/0.15/0.15 Typically, the performance depends on a 1. A...

16 Tage ago | 0

Answered
what types of Network and training are suitable for returning a more precise value?
Plot your targets vs your inputs to see if some of the inputs are not worth using. and/or you can try rejecting inputs based ...

16 Tage ago | 0

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Answered
Issue while mapping weights to a New Feedforward Neural network created using newff
You need to add another component equal to unity to account for a bias weight. Thank you for formally accepting m answer. ...

16 Tage ago | 0

Answered
how to adjust derivatives of backpropagation according to custom error function
Your error function is not at a minimum when output = target Why did you not use the standard E = (output - target)^2 ...

16 Tage ago | 0

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Answered
How to compute gradients using the Neural Network Toolbox software?
help gradient doc gradient Thank you for formally accepting my answer Greg

18 Tage ago | 0

Answered
An error occurred while trying to determine whether "readData" is a function name.
>> help readData readData not found >> doc readData SUCCESS !!! Hope this helps THANK YOU FOR FORMALLY ACCEPTING MY A...

20 Tage ago | 0

Answered
Create neural Network with multiple outputs
See my comment. Greg

20 Tage ago | 0

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Answered
Overfitting of Regression Plot for a Feedforward Neural Network
OVERFITTING IS NOT "THE" PROBLEM !!! In general, the problem is OVERTRAINING an overfit net. My solution is simple: DO NOT OV...

21 Tage ago | 0

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Answered
Neural Network Last Layer Shows a Different Number of Outputs
Line 2: target, not output trainFcn is undefined. I get 15, not 13 in the figure Hope this helps. Thank you for formal...

21 Tage ago | 0

Answered
When I should stop training a neural network?
The danger is OVERTRAINING an OVERFIT NET. There are several approaches. 1. PREVENT OVERFITTING the I-H-O net by ...

25 Tage ago | 0

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Answered
Artificial Neural Network questions
The typical NN has a set of input nodes ( which for some reason is not defined to be a layer !!! ), a middle layer and an outpu...

25 Tage ago | 0

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Answered
Do Multiple Output Neural Networks share the same weights and biases?
The similarity or orthogonality of the outputs tends to be irrelevant. If two set of outputs are not caused by a significant ...

25 Tage ago | 0

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Answered
What is the difference between pca and processpca commands?
help pca doc pca help processpca doc processpca Hope this helps Thank you for formally accepting my answer Greg

26 Tage ago | 0

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Answered
Difference between 2D input and multiple input with recurrent neural networks for time series
Written MATLAB should treat the cases the same. Unfortunately I don't have time to prove it Greg

28 Tage ago | 1

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Answered
how can i train my network for test and validation data?
The MATLAB default AUTOMATICALLY splits the data into TRAINING + VALIDATION+TEST SUBSETS in the ratios 0.7/0.15/0.15. For r...

etwa ein Monat ago | 0

Answered
Best Neural Network for Multivariate Regression
Use FITNET. Accept all parameter settings. Train 10 models with different random initial weights If unsuccessful. Repeat wi...

etwa ein Monat ago | 0

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Answered
how can i train my network for test and validation data?
Where is your training data? The MATLAB default is a random choice of trn/val/tst = 0.7/0.15/0.15 I choose candidate values ...

etwa ein Monat ago | 0

Answered
Early Stopping for Deep Networks
It is not clear to me that, based on a random 15% of the data, this is a better choice. It would be interesting to make a formal...

etwa ein Monat ago | 0

Answered
How to compute gradients using the Neural Network Toolbox software through a backpropagation process?
You are confused The target function is constant and independent of the weights. Hope this helps. *Thank you for formal...

etwa ein Monat ago | 0

Answered
Setting the best training / validation ratio in a Neural Network
1. ALWAYS START WITH 10 DESIGNS USING THE MATLAB DEFAULT! 2. Then evaluate the results to determine what to modify. ...

etwa ein Monat ago | 1

Answered
MATLAB Dropout layer during prediciton
help dropout ... It is important to note that when creating a network, dropout will only be used during training. Hope this he...

etwa ein Monat ago | 0

Answered
How to use predict(net,X) with Sequence data or data which have single dimensional input?
How do you expect us to help when you do not show us your code ??? Just the fact that the error involves "predict" and you show...

etwa ein Monat ago | 1

Answered
I am unable to understand the code
See help dlmread doc dlmread Thank you for formally accepting my answer Greg

etwa ein Monat ago | 0

Answered
Problem with Fitnet function
Delete the outer parentheses >> ( net = fitnet(10) ) % ERROR >> net = fitnet(10) % OK !!! Tha...

etwa ein Monat ago | 0

Answered
How do I improve my neural network performance?
The mse for the trial answer output = mean(target')' is MSE00 = var(target',1) Therefore , I uase the following as a gen...

etwa 2 Monate ago | 0

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