SIC<- read.table(".....pathway.....\\Seabird and seaice data.csv", sep=";",h=TRUE)
summary(SIC)
y<-NULL
y<-SIC$Winter
y<-c(y)
x<-NULL
x<-SIC$Summer
x<-c(x)
z<-NULL
z<-SIC$Year
z<-c(z)

library(segmented)
lin.mod <- lm(y~z)
segmented.mod <- segmented(lin.mod, seg.Z = ~z, psi=2000)
summary(segmented.mod)
slope(segmented.mod)

plot(z,y, pch=16, ylim=c(0,100))
plot(segmented.mod, add=T)

library(segmented)
lin.mod <- lm(x~z)
segmented.mod <- segmented(lin.mod, seg.Z = ~z, psi=2000)
summary(segmented.mod)
slope(segmented.mod)

plot(z,x, pch=16, ylim=c(0,100))
plot(segmented.mod, add=T)

davies.test(lin.mod, seg.Z= ~z, k=30, alternative = c("two.sided", "less", "greater"), beta0=0, dispersion=NULL)