negative values

myassin

Dear Dr. Ferreira,

when I deployment excel sheet

How can I avoid negative values in the output?

Dr. Candida Ferreira

Hi,

You can choose a fitness function that allows you to specify the output bounds, such as the Enhanced MSE fitness. In this case the learning algorithm will try to create models that fit into that range.

For existing models though you can change the embedded Excel VBA code by hand, for example by adding the code below at the end of your gepModel function:

If gepModel < 0.0 Then

gepModel = 0.0 ' or some min value

End If

Another way is to 0/1 normalize your data as in this case, through the reverse normalization function in the Excel VBA code, the output is scaled back into the target range (it’s the training target range, so you might get out of range values for the test dataset or new scoring data).

Candida Ferreira

myassin

Thank you so much for the elaborate and fast reply, Dr. Ferreira

myassin

Dear Dr. Ferreira,

In some cases, I use 9 variables as input and I notice that the program used only 7 variables in the model or less. How can I avoid that? Because I need all input variables in the model.

Dr. Candida Ferreira

Hi,

You can evolve your models with Variable Pressure (it’s an adjustable parameter and you set it up in the Fitness Function Tab). Or you can just click the Complexify button in the Run Panel if you have a model that you think will benefit from integrating more variables.

Candida Ferreira

myassin

Really, many thanks Dr. Ferreira for your efforts and fast reply.

Howdy, Stranger!

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