1. Rrrrrr…… now we know what it is but how the heck do you use it?
Andrew Trant
PPS Arctic - Labrador Highlands Research Group

2. Become a modele’R’ Using Reel Fish Example: General Linear model
>testaov<-aov(N~transect+year,data=fish))
#for an interaction term: transect*year
Now try:
>summary(testaov)
>plot(testaov)
>names(testaov)

3. Continuous ve’R’sus Catagorical
Numeric versus Factor
Look at the degrees of freedom - something strange…
>is.numeric(fish$transect)
>is.factor(fish$transect)
>as.factor(fish$transect)
>fish$transect2<-as.factor(fish$transect)
Rerun with:
> testaov2<-aov(N~transect2+year,data=fish)

4. Generalized Linear Model
GAUSSIAN
>testglm<-glm(N~transect+year,family=gaussian,data=fish)
Again, check:
>plot(testglm)
>summary(testglm)
Check residual plots…..still the same of the ANOVA

5. Generalized Linear Model
GAMMA
>testglm2<-glm(N~transect+year,family=Gamma,data=fish)
Again, check:
>plot(testglm2)
>summary(testglm2)
Check residual plots…..they look GOOD!

6. A few last t’R’icks Getting more than one plot per graphics window:
>par(mfrow=c(2,2))