[R-sig-Geo] a simple correlogram

[Christian Salas]

hi there,

Sorry if this is too simple and silly.

I just want to produce a correlogram using the following example, x and 
y coord. are measured in m (i know that does not matter now, but keep 
reading). I already have checked the sp.correlogram(), correlog(), and 
similar functions in different packages (spdep, ncf) , but none of them 
do what i want, which is very simple.

   x        y       z
111.03    10.7       7
118.11    0.28     1.2
165.36    0.36     8.4
   282.9     0.3     7.5
303.29   13.32    12.2
319.28    3.88     6.2
     447       9       6
   445.5    18.3    13.8
   445.5    12.1     7.1
467.64     1.2     4.7
   485.4    14.1     4.4
    2.98   23.95    11.7
      15   35.78    23.5
130.21    23.6    14.1
   213.5   23.22    21.5
233.57   28.76    35.4
   482.3    20.5       6
   69.73   45.21     7.5
    69.8   50.49    10.2
   76.65    45.5    21.5

t1 <- read.table("datann.txt", header=TRUE)
head(t1)
plot(t1$x,t1$y)

I do only want the correlation to be computed by grouping the distances 
between all pairs of trees into 1m classes, and then being able to save 
that and plot the correlation (r) versus distance, very plain :)

i know that i could do a loop, and compute things, but i wonder if there 
are something already prepared, or at least to select points within a 
certain range of distance.

thanks for your help

c
-- 
-------------------------------------------------------------------------------
Christian Salas                     E-mail:christian.salas at yale.edu
PhD student                         http://environment.yale.edu/salas
School of Forestry and Environmental Studies
Yale University                     Tel: +1-(203)-432 5126
360 Prospect St                     Fax:+1-(203)-432 3809
New Haven, CT 06511-2189            Office: Room 35, Marsh Hall
USA

Yale Biometrics Lab                  http://environment.yale.edu/biometrics