### browsing versus H
require(betareg)
require(lmtest)
require(AICcmodavg)
data<-read.table("C:\\data\\data.txt",header=T)
attach(data)
names(data)
datapl<- data[Sp == "Pl", ]
dataqi<- data[Sp == "Qi", ]
nullpl<-betareg(Br~1|-1+Stand+Year+Tr, data=datapl)
nullqi<-betareg(Br~1|-1+Stand+Year+Tr, data=dataqi)
AICc(nullpl)
AICc(nullqi)
brhpl<-betareg(Br~H|-1+Stand+Year+Tr, data=datapl)
brhqi<-betareg(Br~H|-1+Stand+Year+Tr, data=dataqi)
AICc(brhpl)
AICc(brhqi)
lrtest(brhpl, nullpl)
lrtest(brhqi, nullqi)
summary(brhpl)
summary(brhqi)

### browsing versus YfC
brtpl<-betareg(Br~YfC|-1+Stand+Year+Tr, data=datapl)
brtqi<-betareg(Br~YfC|-1+Stand+Year+Tr, data=dataqi)
AICc(brtpl)
AICc(brtqi)
lrtest(brtpl, nullpl)
lrtest(brtqi, nullqi)
summary(brtpl)
summary(brtqi)

### browsing versus Du
brdupl<-betareg(Br~Du|-1+Stand+Year+Tr, data=datapl)
brduqi<-betareg(Br~Du|-1+Stand+Year+Tr, data=dataqi)
AICc(brdupl)
AICc(brduqi)
lrtest(brdupl, nullpl)
lrtest(brduqi, nullqi)
summary(brdupl)
summary(brduqi)

### browsing versus Dp
brdppl<-betareg(Br~Dp|-1+Stand+Year+Tr, data=datapl)
brdpqi<-betareg(Br~Dp|-1+Stand+Year+Tr, data=dataqi)
AICc(brdppl)
AICc(brdpqi)
lrtest(brdppl, nullpl)
lrtest(brdpqi, nullqi)
summary(brdppl)
summary(brdpqi)

### browsing versus WB
brwbpl<-betareg(Br~WB|-1+Stand+Year+Tr, data=datapl)
brwbqi<-betareg(Br~WB|-1+Stand+Year+Tr, data=dataqi)
AICc(brwbpl)
AICc(brwbqi)
lrtest(brwbpl, nullpl)
lrtest(brwbqi, nullqi)
summary(brwbpl)
summary(brwbqi)

# Correlation between variables, Du vs Dp:
plot(Du,Dp)
m1<-glm(formula = Du ~ Dp, family = quasipoisson, data = data)
summary(m1)
cor(Du,Dp, method="pearson")
cor(Du,Dp, method="spearman")