[R] Multiple line plots

[Gabor Grothendieck]

On 6/15/05, Mihai Nica <m_nica at hotmail.com> 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
> 

Suppose the data frame is dd.  Then:

matplot(dd[,1], dd[,-1], type = "l")

Another possibility is to notice that this is a regularly
spaced time series and it could be useful to represent
it as a ts class object for here and for other purposes:

ddts <- ts(as.matrix(dd[,-1]), start = dd[1,1])
plot(ddts, plot.type = "single", col = 1:3)