forest <- read.csv("forestfires.csv")
set.seed(30032017)
row.number<- sample(1:nrow(forest), size=0.2*nrow(forest))
forest_test<-  forest[row.number,]
dim(forest_test) ## Size of the testing set
forest_train<- forest[-row.number,]
dim(forest_train)  ## Size of training set
row.names(forest_train) <- 1:nrow(forest_train) # rename the rows of training #set
mod2 <- lm(area~factor(X)+factor(Y)+month+day+FFMC+DMC+DC+ISI+temp+RH+wind+rain,data=forest_train)
influence.measures(mod2)
influenceIndexPlot(mod2,id.n=5)