[R] Rhelp: Need help interpreting plots in spatstat

[Lisa Schweitzer]

Hello everybody--

I have been playing with my data in spatstat, and what I'd like to 
present is a basic exploratory spatial analysis. I have used the 
following code, using a ppp.object called tsdspoints.  The code 
develops the simulations and the envelopes I want, but  I don't 
understand my first plot here, the [tsds.ghat.short$r, 
tsds.ghat.short$raw]...I cobbled together this code from some class 
examples used by a prof of mine, and I don't really know how to 
interpret what is going on. The subsequent lines, I'm pretty sure, 
represent the empirical Ghat and the simulation envelope...but that 
first plot stumps me. 

You can see a pdf of the resulting plot if you download it from my 
website : www.bol.ucla.edu/~lschwei/sample.pdf WARNING: this is 
immediate download. 

THE CODE: ######

ghat.env <- function(n, s, r, win=owin(myOwin){
hold <- matrix(0, s, length(r))
for(i in 1:s){
hold[i,] <- Gest(runifpoint(n, win=myOwin), r=r)$raw
}
mn <- apply(hold, 2, mean)
Up <- apply(hold, 2, max)
Down <- apply(hold, 2, min)
return(data.frame(mn, Up, Down))
}
tsds.ghat <- Gest(tsdspoints)
tsds.ghat.short <- tsds.ghat[tsds.ghat$r <= .15, ]
tsds.cdf <- 1-exp(-40*pi*(tsds.ghat.short$r^2))
plot(tsds.ghat.short$r, tsds.ghat.short$raw, xlab="Distance (degrees)", 
ylab="Ghat", main=" Transport, Storage, and Disposal sites (TSDs)")
lines(tsds.ghat.short$r, tsds.cdf)
tsds.env <- ghat.env(n=40, s=100, r=tsds.ghat$r)
tsds.env.short <- tsds.env[tsds.ghat$r <= .15, ]
lines(tsds.ghat.short$r, tsds.env.short$Up, lty=5)
lines(tsds.ghat.short$r, tsds.env.short$Down, lty=5)
###############

Many Thanks, 

Lisa
who was working on her stinking dissertation while everybody else was 
learning cool things in Vienna.