R help - Nov 2011 - Myriam Saavedra M. Sc. Questions about maximun radius distance

Dear Mr. Baddeley
 
I just graduated from a Masters in Applied Mathematics on Jun19th. My thesis was
about spatial distribution /a nalysis of some trees in a part of  the Congo
Basic Forest.
In my thesis I used your spatial package in R, and today I'm doing a more
deeper study about how we choise the r distance in Function F(). I would like to
be able to understand about value of rmaxdefault as:
 
ripley <- min(diff(W$xrange), diff(W$yrange))/4
rlarge <- if (!missing(lambda)) sqrt(1000/(pi * lambda)) else Inf
rmax <- min(rlarge, ripley)

 For the ripley's calculation, I found your explanation in the internet but
for the rlarge I couldn't find it. Could you explain why it is using the
value inside of the sqrt (1000/(pi * lambda)).
 
Many thanks in advance if you do have the time to answer,
 
Myriam Saavedra  
Universidad San Francisco de Quito
.......................
Adress Home
3808 Lillooet St.
VANCOUVER BC
CANADA, V5R-2E6

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Myriam <fantasmita1948 <at> yahoo.fr> writes:
>  Dear Mr. Baddeley ? I just graduated from a Masters in
> Applied?Mathematics?on Jun19th. My thesis was about spatial
> distribution /a nalysis of some?trees in a part of? the Congo Basic
> Forest.  In my thesis I used your spatial package in R, and today
> I'm doing a?more deeper study about how we choise the r distance in
> Function F().?I would like to be able?to understand about value of
> rmaxdefault as:
  "Mr Baddeley" isn't here (probably) -- this is a generic
help list for questions on R. 
> ripley <- min(diff(W$xrange), diff(W$yrange))/4
> rlarge <- if (!missing(lambda)) sqrt(1000/(pi * lambda)) else Inf
> rmax <- min(rlarge, ripley)
 
> ?For the ripley's?calculation, I found your explanation in
> the?internet but for?the rlarge I?couldn't find it. Could
> you?explain?why it?is using?the value?inside of the?sqrt (1000/(pi *
> lambda)).
  You've given us just a fragment of a question here -- there's
not enough context to work with. We don't know where the
variable 'W' came from, although presumably from a Ripley's
K calculation ... ? 

 Please read http://tinyurl.com/reproducible-000 , and give us more
information (e.g. the link (URL) to the explanation you say you found
on the internet).

   I would also suggest that this question might be better suited
for the r-sig-ecology at r-project.org mailing list ...