Exemples :

1.                               x<-seq(0,10,1)

2.                               y<-2+3*x

3.                               profit<-0.3*y-x

4.                               df<-data.frame(Effort=x, Ventes=y, Profit=profit)

5.                               y<-2+4*x

6.                               profit<-0.3*y-x

7.                               df$Ventes2=y

8.                               df$Profit2=profit

9.                               df

10.                             # show Ventes

11.                             matplot(x, df[,seq(2,5,2)], pch = 1:2, type = "o", col = 1:2,xlab="Effort", ylab="Reponse")

12.                             legend(min(x), max(df[,seq(2,5,2)]),names(df)[seq(2,5,2)], lwd=3, col=1:2, pch=1:2)

13.                             # show Profits

14.                             matplot(x, df[,seq(3,5,2)], pch = 1:2, type = "o", col = 1:2,xlab="Effort", ylab="Reponse")

15.                             legend(min(x), max(df[,seq(3,5,2)]),names(df)[seq(3,5,2)], lwd=3, col=1:2, pch=1:2)

   Effort Ventes Profit Ventes2 Profit2

1       0      2    0.6       2     0.6

2       1      5    0.5       6     0.8

3       2      8    0.4      10     1.0

4       3     11    0.3      14     1.2

5       4     14    0.2      18     1.4

6       5     17    0.1      22     1.6

7       6     20    0.0      26     1.8

8       7     23   -0.1      30     2.0

9       8     26   -0.2      34     2.2

10      9     29   -0.3      38     2.4

11     10     32   -0.4      42     2.6