##5.1
esaligna=read.csv("esaligna.csv", header =T, sep=",", as.is=T)
str(esaligna)
plot(esaligna$dap~esaligna$ht, xlab= "Altura (m)", ylab= "dap (cm)" )
?plot
par(cex=1.4)
plot(esaligna$dap~esaligna$ht, main= "Relação Altura versus dap" ,xlab= "Altura (m)", ylab= "dap (cm)", cex=1.4, bty="l",tck=0.02 )

####5.2
x11()
par(mfrow=c(1,2))
boxplot(esaligna$dap~esaligna$talhao, main= "a",xlab= "dap (cm)", ylab= "Talhao",  bty="l")

med.esa=tapply(esaligna$dap, esaligna$talhao, mean)
sd.esa=tapply(esaligna$dap, esaligna$talhao, sd)
plot(med.esa, main= "b",xlab= "dap (cm)", ylab= "Talhao", bty="l", ylim=c(0,30))
x=1:6
arrows(x0=x,y0=med.esa-sd.esa,x1=x,y1=med.esa+sd.esa,code=0)