# [R] spatstat regression troubles

Gregory Ryslik rsaber at comcast.net
Sat Apr 16 05:50:25 CEST 2011

Hi Everyone,

I am trying to figure out the spatstat package for the first time and am having some trouble. Unfortunately, I can't post my data set but I'll hopefully post enough details for some help.

I want to model the intensity of a spatial point process using 2 covariates from my data. After reading through the documentation, I have successfully created 2 "ppp" objects. The first ppp object is a list of coordinates where people exist and the second is where people do not exist as follows:

> people_exist
planar point pattern: 944 points
window: rectangle = [73, 135] x [18, 54] units
> people_empty
planar point pattern: 2828 points
window: rectangle = [73, 135] x [18, 54] units
>

Now, I also have observed values for two covariates, Z1 and Z2 for both the 944 and 2828 points in dataframe form. Finally, following the documentation, I was able to create one quadrature Q, with 944 points and 2828 dummy points that correctly takes the points where we had an event (people_exist) and the points where we don't have an event (people_empty).