[R-sig-Geo] Newbie questions

[Tim Keitt]

You might also have a look at:

https://sites.cns.utexas.edu/keittlab/publications/hierarchical-model-whole-assemblage-island-biogeography

I did island-to-island distances in R or PostGIS (don't recall which) and
the modeling in JAGS.

THK

http://www.keittlab.org/

On Fri, Sep 9, 2016 at 10:39 AM, quantrum75 via R-sig-Geo <
r-sig-geo at r-project.org> wrote:

> Hello Tim,Thank you so much for the reply! I shall surely check out
> gDistance in rgeos for the distance distribution. That is definitely a
> question for consideration since we think the boundary influences the
> location of the growths.
> For the issue related to differential growth of islands (as polygons),
> what would your advice be? Any hints, tips or suggestions? Would a weighted
> point process distribution analysis be appropriate? What kind of a
> regression model would be appropriate?
> I hugely appreciate any insights.RegardsQuant
>
>
>       From: "Howard, Tim G (DEC)" <tim.howard at dec.ny.gov>
>  To: "r-sig-geo at r-project.org" <r-sig-geo at r-project.org>
> Cc: quantrum75 <quantrum75 at yahoo.com>
>  Sent: Friday, September 9, 2016 5:45 AM
>  Subject: RE: Newbie questions
>
> If we assume that the islands are growing in all directions equally, then
> for the 'distance from boundary edge' type of question you are most
> interested in island initiation, which might be a point-based question.
> Well, points to polygon, as your boundary edge is the edge of a polygon.
>
> On the other hand, for questions about differential growth of islands I
> would think you then are dealing with questions about the islands as
> polygons.
>
> Certainly using many of the GIS/spatial tools can get you quite far down
> this path. For example, getting a distribution of island (point) distances
> to the boundary (with perhaps, gDistance in rgeos) would give you something
> you could compare among cultures.  Of course you'd be using sp to structure
> the data (in spatial data frames).
>
> Good luck!
> Tim
>
> > ------------------------------
> >
> > Message: 4
> > Date: Fri, 9 Sep 2016 07:53:31 +0000 (UTC)
> > From: quantrum75 <quantrum75 at yahoo.com>
> > To: "r-sig-geo at r-project.org" <r-sig-geo at r-project.org>
> > Subject: [R-sig-Geo] Newbie questions
> > Message-ID: <571527464.1514114.1473407611621 at mail.yahoo.com>
> > Content-Type: text/plain; charset="utf-8"
> >
> > Hello all,I am an absolute newbie to spatial statistics, but I am quite
> > thoroughly obsessed by it currently. I am an engineer by training, so I
> can find
> > my way around math and programming. I have begun to look at the Spatial
> > CRAN view and am absolutely blown away by the enormous body of work in
> > there. So thank you all for that. But I am equally confused regarding
> the right
> > choice of software and statistical approach as well.
> > With that introduction, I will try to explain (one of) the problem(s) I
> am trying
> > to solve. Of note, we absolutely do not deal with GIS issues.
> >
> > We have a setup where we are trying to grow some bacterial cultures on a
> > polygonal irregular surface. I am able to obtain 2-D projection
> views/images
> > similar to the illustration attached to this mail. Some of the things I
> want to do
> > are
> >
> > 1) Establish a spatial statistical analytic pipeline to answer questions
> like
> > a) Are the patterns of bacterial island growth in different cultures
> statistically
> > random or correlated?b) Are the distances from the boundary edge to a
> > bacterial island random or have a pattern?
> >
> > Now, the issue I have is, the bacterial islands have an "area", so I
> cannot
> > really consider them as "point" processes. Yet, these "areas" are
> sufficiently
> > far away from each other (relative to the polygonal boundary) that I can
> (to
> > an approximation) consider them as being "point" processes (maybe?)...
> >
> > Some of my questions are
> > 1) Is it appropriate to use a "point processes" method or an "areal
> processes"
> > method for analysis of this problem?
> > 2) If point processes are ok, is it ok to weight the area and use the
> centroid at
> > the location of the point?
> > 3) Where do I start? I currently have 5 books - The Baddeley book
> (spatstat,
> > for point processes), the Cressie book (for theory), the R-INLA book
> > (Bayesian spatial statistics), Applied Spatial Analysis in R (Dr
> Bivand's book)
> > and the Gelfand book (Hierarchical modelling)
> > 4) Packages - Spatstat? sp? spdep? splancs? spatial? DCluster? AMOEBA?
> > Which spatial regression package? Arghhhh.....
> > Now, I am not asking anyone to provide me with a ready made solution. I
> > would simply appreciate if someone could point me in the right direction
> on
> > how to start and go far from there. I am willing to learn and put in the
> > necessary elbow grease to understand it well. Experts in spatial
> statistics are
> > unavailable at my local college, so an immediate collaboration is bit
> far off.
> > But something we can look into in the future.
> >
> > Thank you for your kind consideration. Any and all advice is eagerly
> > welcomed and I will be highly grateful for the same.RegardsQuant.
> > PS - Long term, I would like to contribute in some way to this group. If
> > anyone is in need of any assistants for any packages, I am willing to
> volunteer
> > my time.
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