Re: Software suggestions

In article <1125140487.375978.136460@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
clemenr@xxxxxxxxxx says...
> >From what you write, I think that the following is the case:
>
> You have a table of data.
>
> You want a formula that relates some variable "Results" to some other
> variables "var1", "var2", "var3" ... "varn"
>
> If you were interested in linear regression, then you'd want to find
> weights b0, b1, b2, b3, ..., bn such that:
>
> Results = b0 + b1 * var1 + b2 * var2 + b3 * var3 ... + bn * varn
>
> minimises some goodness of fit measure. E.g. least squares.
>
> However, you don't know the form the expression should take. Hence you
> want a program that finds the formula for you. You're disappointed by
> what you find in R because the various procedures in R can typically
> only be used if you give the structure of the formula, and R then finds
> a "good" set of weights.
>
> Is this the case?
>
> If this is the case, then you are in trouble. Because finding such
> formulae in data, at least in the relatively unrestricted (in terms of
> possible structures present in the formula, over and above weights)
> form that this problem is usually attempted in the field of machine
> learning is far from a solved problem. Unless the relationship you're
> searching for in your data is quite simple, even if you get hold of
> such a program, it's unlikely to be much use to you. And if the
> relationship is simple, you can probably find it by hand.
>
> I think you need to be clearer about what it is that you want.

You are correct about what I want. I want the computer to find it in an
unrestricted structure.

I am surprised that no one has written such a program too.

Say I put in 20 variables in a table with say 1000 entries. A computer
program tried to solve it for say 2,000,000 different equations and then
returns the equation that gives the best fit.

Would it be useful? To me yes.



>
> Cheers,
>
> Ross-c
>
>

--
Ask yourself, what would God think of your ideals, religion and beliefs?

Observations of Bernard - No 83
.

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