R help - Mar 2008 - (x,y) coordinates for grid.text()

All,

When using grid.text it seems my supplied (x,y) coordinates are being
plotted only in npc (normalized parent coordinates) where (.5,.5) is the
center of the graph.  How do I allow (x,y) to be coordinates corresponding
to the (x,y) values in the graph?   The examples in ?grid.text seem to do
this.  (I think the problem lies in how x and y are defined with respect to
unit ).   Any help much appreciated.  Sample code below.

Cheers,
David




y = c( 0.4,  0.6, -0.1,  0.3,  0.3, -0.2,  0.7,  0.7,  0.2,  0.0,  0.9,
-0.1,  0.6, -1.1,  0.8, -1.0,  0.4,  0.1,  0.7, -0.2, -0.1, -0.1,  2.2,
0.7,  1.1,  0.2, -0.2, -0.9,  0.4,  0.1, -0.3, -0.4)
x = c(4.1000,  4.9600,  1.2000,  3.9000,  3.1875,  1.9000,  1.8625,
0.7650,  1.5750,  2.4700,  1.6250,  1.5500,  2.3125,  1.3125,  1.0600,
-0.5500,  1.1000,  0.0200, -0.0375,  3.4600,  2.5250,  2.0950,  0.8000,
1.6050, -0.4150, -0.7300,  1.1550,  1.4850,  2.2000,  2.2500,  0.6000,
2.1000)
junk.frm = data.frame(ID = rep(1:16, each = 2), x, y, z = rep(c("D",
"P"),
16))
xyplot(y ~ x , data = junk.frm[junk.frm$z =="D",], type =
c("g", "p",
"smooth"), pch = 20)

grid.text("put text here", x = 1, y = 1.5)  # doesn't show up
grid.text("put text here", x = .4, y = .7) # shows up in the desired
location but this is for npc

>  When using grid.text it seems my supplied (x,y) coordinates are being
>  plotted only in npc (normalized parent coordinates) where (.5,.5) is the
>  center of the graph.  How do I allow (x,y) to be coordinates corresponding
>  to the (x,y) values in the graph?   The examples in ?grid.text seem to do
>  this.  (I think the problem lies in how x and y are defined with respect
to
>  unit ).   Any help much appreciated.  Sample code below.
Have you read the documentation for grid.text?  You need to read the
description of the default.units argument and then read ?unit.

Hadley

-- 
http://had.co.nz/