### Re: (zdog) Re: (4) Estimating continuous functions

by tilly (Archbishop)
 on Mar 30, 2004 at 17:17 UTC ( #341027=note: print w/replies, xml ) Need Help??

in reply to (zdog) Re: (4) Estimating continuous functions

First of all for the general case, some back of the envelope estimates suggest to me that 1/distance is a better weighting than my original 1/distance**2.

As for your specific function, you may find it worthwhile to do some transformations first. For instance if I understand your description, then log(F(x,y,z)) is roughly of the form K*log(log(x))/(y*z). So log(F(x,y,z))*y*z/log(log(x)) is roughly a constant.

This is good because the estimator that I provided is going to give the best results when approximating functions that are roughly constant. (Cubic splines, etc, give very good results at approximating functions that locally look like low-degree polynomials.) And estimating this "rough constant" gives you (after reversing the above calculation) your original function F.

In general a judicious application of general theory and specific knowledge about your situation is more effective than abstract theory by itself...

• Comment on Re: (zdog) Re: (4) Estimating continuous functions

Create A New User
Node Status?
node history
Node Type: note [id://341027]
help
Chatterbox?
 [LanX]: M-x untabify [choroba]: I don't think they're multiple people. I was told "he or she" sounds old-fashioned and "they" is the way to say it [pryrt]: Those others were definitely offensive or unequivocably rude, I agree. [choroba]: (well, it comes from the 14th century, so labelling it as "modern" doesn't seem appropriate) [Your Mother]: "They" is becoming accepted but it irritates me sometimes. I tend to just pick she or he randomly or try to use "one." LanX thinks it is appropriate here :) [Your Mother]: They would think so. [jdporter]: ok, I need a recipe for piping lines "through" an external program which is itself a filter [jdporter]: without using a tmp file [1nickt]: tobyink perl -MTypes::Standard= is_Int -Mstrict -wE 'say 1 if is_Int 1.0'

How do I use this? | Other CB clients
Other Users?
Others contemplating the Monastery: (13)
As of 2017-05-24 20:24 GMT
Sections?
Information?
Find Nodes?
Leftovers?
Voting Booth?
My favorite model of computation is ...

Results (186 votes). Check out past polls.