Re: POLY_FIT gives wrong answer !

[davidf(at)dfanning.com (David Fanning)]

Henk Schets (Henk.Schets@oma.be) writes:

> Maybe all of you already know this, but I didn't and I could not find
> any documentation about it.
> The problem : I have two long arrays (x- and y-values) and I made
> subarrays out of them by using an array as subscript, like
>     x = fltarray(l)
>     y = fltarray(l)
>     indexarr = longarray(l)
> (you know, the way to sort different arrays together)
> However, when I do something like out =
> poly_fit(x[indexarr],y[indexarr]), the outcome is simply wrong !  I know
> this because other programs gave another solution (all the same).
> The only way to do it right is by making other arrays like x2 and y2 and
> doing a poly_fit on it.
> 
> Is this a known issue ?

I don't know. What is known is that things are not always
the way they seem to be. I'm guessing this is one of those 
times. :-)

Cheers,

David

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David Fanning, Ph.D.
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