##### Code for Lecture on Poisson regression


### Example - effects of age and birth location (wild or captive) 
### on litter sizes in red wolves
### Litter size is not normally distribution (skewed to the left) 
### and isn't continuous


###import the data


datum=read.csv(file.choose())


###Analyze the data using glm


help(glm)
### glm is the same as lm, but requires an additional argument
### family, which specifies what the error structure is
results=glm(LitterSize~Age+BirthLoc,data=datum,family=poisson) 
### runs a Poisson regression
summary(results) #examine the results