[R-sig-Geo] [FORGED] Re: using spatialpolygonsdataframe in ppm (or, converting spatialpolygonsdataframe to pixel image or other object useful in ppm)

[Michael Sumner]

Thanks Rolf, it's actually  not what I meant and I appreciate the
clarification :) - owin is clear in its definition of specific types, but
spatstat types generally do allow combinations of domain, discretization,
and path-based boundaries. So I hope I'm not wrong about *that*.

(I aspire to be more expert on this cross-over topic, still working on it :)

Cheers, Mike.



On Sat, 2 Sep 2017 at 20:27 Rolf Turner <r.turner at auckland.ac.nz> wrote:

> On 02/09/17 19:00, Michael Sumner wrote:
>
> <SNIP>
>
> >
> > It's not clear to me if you need polygons in spatstat or a raster owin
> > version of them - admittedly spatstat does allow a combination of the
> two,
>
> That's not actually true.  The spatstat package allows for observation
> windows (objects of class "owin" which are either polygonal (of type
> "polygonal") *or* "raster-like" (of type "mask"), consisting of a
> pixellation of the bounding box with the pixels having the values TRUE
> or FALSE.  There is also type "rectangle" which is conceptually a
> special case of "polygonal" but has (obviously?) practical advantages
> when it is applicable.
>
> However an "owin" object *cannot* be a combination of polygonal and mask
> types.
>
> <SNIP>
>
> cheers,
>
> Rolf Turner
>
> --
> Technical Editor ANZJS
> Department of Statistics
> University of Auckland
> Phone: +64-9-373-7599 ext. 88276 <+64%209-373%207599>
>
-- 
Dr. Michael Sumner
Software and Database Engineer
Australian Antarctic Division
203 Channel Highway
Kingston Tasmania 7050 Australia

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