# RE: [R] How to plot points as numbers/strings in lattice

From: Ignacio Colonna <iacolonn_at_uiuc.edu>
Date: Wed 16 Mar 2005 - 10:21:42 EST

Owen,

I think this gives the plot you are looking for. There may be other better ways to do it, this is just the one I know. Inside 'panel' you would need to use 'ltext()' instead of 'text()', as in the example you provided.

xyplot(V1~V2, data=a, groups=V3,
panel = function(x, y, groups)

ltext(x, y, label=groups, cex = .75) )

Ignacio

Hello,

I would be very grateful if anyone could help with what seems like a simple lattice task. I want to use xyplot, where the symbols for the plotted points are taken from another column in the data frame. So if the data frame looked like:

a <- as.data.frame(matrix(data=c(1,1,10,2,2,20,3,3,30), nrow=3, ncol=3, byrow=TRUE))
a

V1 V2 V3
1 1 1 10

2 2 2 20
3 3 3 30

you would get an xy scatter plot using where "10" (not a dot) is at coordinate 1,1, "20" is at 2,2, and so on.

I have made two attempts. The first, below, almost works, but only takes the first character from the V3 column:

library(lattice)
xyplot(V1~V2, data=a, pch=as.character(a\$V3))

I've also tried this example, which is given in an online user guide for trellis. It uses the built-in "ethanol" data set (which is also in lattice), and subscripts... but when I try the same code in lattice, I get an "invalid graphics state" error.

library(lattice)
xyplot(NOx ~ E | C, data = ethanol, aspect = 1/2,

```        panel = function(x, y, subscripts)
text(x, y, subscripts, cex = .75)
```
)

Thank you very much in advance!

Owen Solberg

> version

_
platform i686-redhat-linux-gnu

```arch     i686
os       linux-gnu
```

system i686, linux-gnu
status
major 2
minor 0.0
year 2004
month 10
day 04
language R

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