plot(ChickWeight$weight)
plot(ChickWeight$Time,ChickWeight$weight)

# grafico con punti a colori
col1<-c("red", "green", "blue", "yellow")

plot(ChickWeight$Time,ChickWeight$weight,
     main="Weight by Time", xlab="Time", ylab="Weight",
     col = col1[ChickWeight$Diet])

legend("topleft", title="Diet", cex = 0.8,
       legend=levels(ChickWeight$Diet), fill = col1)

# grafico con diversi simboli
punti<-c(0,1,2,6)

plot(ChickWeight$Time,ChickWeight$weight,
     main="Weight by Time", xlab="Time", ylab="Weight",
     pch = punti[ChickWeight$Diet])

legend("topleft", title="Diet", cex = 0.8,
       legend=levels(ChickWeight$Diet), pch=punti)