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Re:A visual proof that neural nets can compute any function by pedrosorio on Sunday March 06, 2022 @11:59AM (#30578912)
> There isnt a unique house price in terms of those variables

> An overly mathematical view of the world has obscured the scientific method from our thinking here

Since it is understood that houseprice is not a function of just three variables, the mathematical view (statistical learning theory) commonly used when training models, defines house price as a random variable. This takes into account the uncertainty from all the unknown factors they contribute to house prices.

The distribution defining this random variable is a function of the 3 input observations. Commonly, the inputs are used to compute the mean, and the shape of the distribution is fixed - a Gaussian, for example - but not necessarily.

Given observations of the 3 inputs, each observed y_houseprice is just a sample from this random variable.

Re:A visual proof that neural nets can compute any function by mjburgess on Sunday March 06, 2022 @01:39PM (#30579867)
Well a random variable is a function, from event space to the real line. We return to a single measure by taking its expectation. We dont model `Y = f(X)`.

This doesn't play well with the universal theorem in the article. NNs can only be said to model expectations of random variables.

Re:A visual proof that neural nets can compute any function by thfuran on Sunday March 06, 2022 @01:43PM (#30579909)
>We return to a single measure by taking its expectation

Only if you want to throw away most of the information in your model.

Re:A visual proof that neural nets can compute any function by mjburgess on Sunday March 06, 2022 @01:59PM (#30580074)
Well, indeed.

One then needs to explain how a NN being a "universal fn approximator" helps at all in this context.

One models RVs generativey using distributions (and so on), the actual model (eg., of house prices) isnt a function, it's often an infinity of them.

Re:A visual proof that neural nets can compute any function by thfuran on Sunday March 06, 2022 @02:23PM (#30580303)
>One then needs to explain how a NN being a "universal fn approximator" helps at all in this context.

Given that I can't tell why you don't think it does, I don't think I can explain it to you. From the other contexts you've talked about here, you seem to be implying that the only thing that is potentially useful is an AGI which either carries out or merely designs experiments. But that's patently absurd.

Re:A visual proof that neural nets can compute any function by mjburgess on Sunday March 06, 2022 @02:41PM (#30580481)
I'm happy to hear the very narrow case on this. Can a NN learn geometric Brownian motion?