Dynamic code Generation

Maybe you could use something like this as a point of departure:

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To see the results as a UDF, put this in a cell and format to wrap text:

=FunctionGenerator(INT(RAND()*8^8))

Sorry, I don't follow that.

What I mean is that each function only needs to be generated once during each run of the program.

After that though each generated function will be called multiple times during the program until the optimal set of parameters are found.

the example code below shows how one the function will be called during the optimisation part of the program

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Is there some way to dynamically link the function generated by your code into the function above?

If not is there another way to achieve the same aim?




I have now added a copy of the spreadsheet where an example optimisation is being carried out. I need to figure out how to get the functions generated by your code into the optimiser. In the same way that "myfunction" in macro1 is being used. (or alternately any other way that works)

You can't bind the variable names in the string to run-time variables.

I don't see the relationship between your code below and the summation of eight functions in some order. In fact, if all you were doing is summing some combination of 8 functions, order doesn't matter, so that's not what you're trying to do (I surmise).

You need to back off to 10,000 feet and explain what you're trying to do, without me having to dissect your workbook.

Hi there,

OK Big picture my problem is two fold:

1.) I need to generate a set of fucntions from a group of base functions. I want to do this through VBA to avoid having to type them all in manually.
End goal I want these to be actual functions not strings.

2.) These functions are then to be passed to Myfunction (shown below) so that each function in turn is fitted and its optimal parameters found.

You don't need to understand the rest of the sheet just the part below (I think).

The rest of the sheet is an optimiser. It evaluates "myfunction" with some input parameters. Is then calculates how good a fit you have to the sample data. It then updates the parameters to try and give a better fit. This process is repeated until a best fit is found.

What I want to do is generate 8^8 permutations of all the possible linear combinations of the functions. I have amended your code to produce the same thing for the simpler case of 2 functions.

The code below produces the correct set of functions and stores them as strings in asFunc. I would like to find a way to pass these functions to myFunction so that each of these functions in turn becomes the objective function is this possible?

Or is there another way to achieve the same goal? I want to convert the strings in asFunc to actual functions so that they can be evaluated by the optimiser.
Or alternately avois using strings all to gether and go stright to the functions.

I hope this is clear, if not please ask and I will gladly explain further.

Baz

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The three ways I can think to do this are:

1. Make sure the expressions have each variable isolated by white space, and replace each variable with its value, e.g.,

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That will not run fast.

2. Put the variables on a worskheet and evaluate there:

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3. If the individual functions are known at design time, you can implement each in VBA and invoke them as a computed string

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