Highlight Features in the Data
For each of the five inputs, we want use a function to highlight rate of change types of features. We will use
the following function (as originally proposed by Jurik) for this purpose.
ROC(n) = (input(t) − BA(t − n)) / (input(t)+ BA(t − n))
where: input(t) is the input’s current value and BA(t − n) is a five unit block average of adjacent values
centered around the value n periods ago.
Now we need to decide how many of these features we need. Since we are making a prediction 10 weeks into
the future, we will take data as far back as 10 weeks also. This will be ROC(10). We will also use one other
rate of change, ROC(3). We have now added 5*2 = 10 inputs to our network, for a total of 15. All of the
preprocessing can be done with a spreadsheet.
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C++ Neural Networks and Fuzzy Logic:Preface
Highlight Features in the Data
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