[R] Multiple line plots

[Marc Schwartz]

On Wed, 2005-06-15 at 13:50 -0500, Mihai Nica wrote:
> Greetings,
> 
> I would like to plot three lines on the same figure, and I am lost. There is 
> an answer to a similar thread but I tried matplot and it is beyond me. An 
> example of the data follows:
> 
> Year	EM	IM	BM
> 1983	9.1	16.8	-7.7
> 1984	12.0	18.0	-6.0
> 1985	13.6	19.1	-5.5
> 1986	12.4	17.3	-4.9
> 1987	14.6	20.3	-5.7
> 1988	20.6	23.3	-2.6
> 1989	25.0	27.2	-2.2
> 1990	28.4	30.2	-1.8
> 1991	33.3	31.2	2.1
> 1992	40.6	35.2	5.4
> 1993	41.6	39.9	1.7
> 1994	50.8	49.5	1.3
> 1995	46.3	61.7	-15.4
> 1996	56.8	73.0	-16.2
> 1997	71.4	85.9	-14.5
> 1998	79.0	94.7	-15.7
> 1999	87.0	109.7	-22.7
> 2000	111.7	135.9	-24.2
> 2001	101.5	131.4	-29.9
> 2002	97.5	134.6	-37.1
> 2003	97.4	138.1	-40.6
> 2004	110.8	155.8	-45.1
> 
> Thanks,
> 
> Mihai


# First argument is x axis vector
# Second argument is the y value vectors

matplot(df$Year, df[, -1], type = "l", xlab = "Year", 
        ylab = "Some Unit of Measure")

If you want a legend, you could use the following:

legend(1985, 150, legend = colnames(df)[-1], lty = 1:3, col = 1:3)

See ?legend as well.

HTH,

Marc Schwartz