[R] Plot error

[Petr PIKAL]

Hi

r-help-bounces at r-project.org napsal dne 28.05.2009 16:21:01:

> > I want to plot data such that the 3 time points(a,b,c) lie on the 
X-axis 
> and
> > the values of these times points are on Y-axis for n samples 
(e.g.100).
> > 
> > So, I have an object x, dim 100 4, it is a dataframe (when checked the
> > class)
> > x = 
> > name   a       b      c
> > 1        0.11  1.11   0.86
> > 2           .      .       .
> > 3           .      .       .
> > .
> > .
> > .
> > 100
> > 
> > so when i say:
> > 
> > > plot(1:3, x[,2:4], type="l") ----- I get the error below
> > 
> >     Error in xy.coords(x, y, xlabel, ylabel, log) : 
> >            (list) object cannot be coerced to type 'double'
> > 
> > However if I do:
> > > plot(1:3, x[1,2:4], type="l") ------ It works for the 1st row, and 
> each
> > > individual row BUT NOT ALL ROWS
> > 
> > Please could someone explain what is happening here?
> > 
> > I wonder if I need to use 'lines' for the remaining, BUT I have 
another
> > dataset y with same dimensions as x, which I want to plot on the same
> > graph/plot to see the difference between x and y.
> 
> Your data looks like this:
> x <- data.frame(name=sample(letters, 10), a=runif(10), b=rnorm(10), 
> c=rlnorm(10))
> 
> The problem is that the subset x[,2:4] is also a data frame, not a 
matrix.
> class(x[,2:4])          #[1] "data.frame"
> 
> The simplest thing is probably to use lines, as you say.
> row <- seq_len(nrow(x))
> xx <- x[,2:4]
> plot(row, xx$a, ylim=range(xx), type="l")
> lines(row, xx$b, col="blue")
> lines(row, xx$c, col="green")

Maybe also matplot is worth try

matplot(1:3,t(x[,2:4]))

regards
Petr





> 
> Regards,
> Richie.
> 
> Mathematical Sciences Unit
> HSL
> 
> 
> ------------------------------------------------------------------------
> ATTENTION:
> 
> This message contains privileged and confidential 
inform...{{dropped:20}}
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.