[GRASS-dev] v.surf.idw broken

[Jachym Cepicky]

Thanks

I can confirm, that using -n flag works

Jachym

2010/4/13 Paul Kelly <paul-grass at stjohnspoint.co.uk>:
> On Tue, 13 Apr 2010, Jachym Cepicky wrote:
>
>> Hi,
>> I can not get reasonable result (compared with v.surf.rst) from
>> v.surf.idw using attached input vector points
>>
>> is it possible, that v.surf.idw is kind of broken?
>
> Hello,
> I can confirm that I can reproduce the strangeness, that it only happens
> when *not* using the -n flag (i.e. when indexing points) and that it happens
> when interpolating a relatively small number of points into a region with a
> relatively high resolution. E.g. for the given data I observe strangeness
> for a resolution of 10, but it goes away either by specifying the -n flag or
> decreasing the resolution to 15.
>
> It does indeed look to be caused by my buggy code from 2003, or (perhaps
> less likely; I'm not sure) some later change to it - specifcally something
> to do with the "shortlist" method of avoiding an intensive search for nearby
> sites/points when the number of points is relatively small compared to the
> region size.
>
> I can't see anything obviously wrong but I'll look into it over the next few
> days...
>
> Paul
>



-- 
Jachym Cepicky
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