R help - Apr 2009 - weird error with contourplot

Sorry if I am cluttering up this list with too many rank beginner
questions.  But I *am* a rank beginner, and I am at my wit's end with
this one:

I have a data frame df, with components x,y,z.  This command to make a
contour plot with lattice graphics works just fine:
> contourplot(z~x*y,data=df,cuts=20)
Then I try
> contourplot(z~x*y,data=df,cuts=20,region=T)
And it dies on me with the error:

Error in unit(x, default.units) : 'x' and 'units' must have
length > 0


I have done maybe a hundred contour plots in this same exact way, and
have never seen this error before.  And it seems to me that adding the
flag region=T should be a benign thing to do.  I have no idea what it
causing the problem.  Anyone see what I'm doing wrong?  Thanks!

--Sam Cable

Call off the dogs.  The problem was that because of the scale of my data
(<<1) contourplot somehow can't handle labeling the contours if it
"paints" the plot region as well.  I can easily get around this by
re-scaling the data.  But, if anyone can explain to me why throwing the
region=T flag makes a difference, I would be interested to know.  Thanks
again!

--Sam



-----Original Message-----
From: Cable, Samuel B Civ USAF AFMC AFRL/RVBXI 
Sent: Thursday, April 16, 2009 9:55 AM
To: 'r-help at r-project.org'
Subject: weird error with contourplot

Sorry if I am cluttering up this list with too many rank beginner
questions.  But I *am* a rank beginner, and I am at my wit's end with
this one:

I have a data frame df, with components x,y,z.  This command to make a
contour plot with lattice graphics works just fine:
> contourplot(z~x*y,data=df,cuts=20)
Then I try
> contourplot(z~x*y,data=df,cuts=20,region=T)
And it dies on me with the error:

Error in unit(x, default.units) : 'x' and 'units' must have
length > 0


I have done maybe a hundred contour plots in this same exact way, and
have never seen this error before.  And it seems to me that adding the
flag region=T should be a benign thing to do.  I have no idea what it
causing the problem.  Anyone see what I'm doing wrong?  Thanks!

--Sam Cable