How to plot a multicolumn CSV file?

Question

I am very new to R, so excuse me for a question probably stupid.

I\'ve got a multicolumn CSV (plain comma-separated, no quotes) file where the first row is the header, t

Answer 1

You can use read.csv to input the data as a data.frame. Then you have plenty of choices for plotting. I prefer lattice for most investigative work.

Two in lattice. Here I am creating random data to chart.

library(lattice)
d <- data.frame(index=1:20, x=rnorm(20), y=rnorm(20))

> head(d, n=3)
  index         x          y
1     1 -1.065591  0.2422635
2     2 -1.563782 -1.4250984
3     3  1.156537  0.3659411

xyplot(x+y~index, data=d, type='l', auto.key=list(space='right'))

You can generate the formula from the names of the columns. I don't usually do this from the prompt, but use such constructs in code:

f <- paste(paste(names(d[,-1,drop=FALSE]), collapse="+"),
           names(d[,1,drop=FALSE]),
           sep=" ~ ")

xyplot(as.formula(f), data=d, type='l', auto.key=list(space='right'))

As in Ben's answer, type='l' specifies lines. The default is type='p' for points. I added the auto.key parameter here, to label the series.