**From:** Adrian Baddeley (*adrian@asteridia.maths.uwa.edu.au*)

**Date:** Tue 17 Jun 2003 - 20:55:11 EST

**Next message:**Hugh Chipman: "[R] User-defined functions in rpart"**Previous message:**wolski: "[R] hist density..."

Message-id: <16110.62351.704257.863527@asteridia.maths.uwa.edu.au>

Thanks to Andy Liaw and Baz

for alternatives to tinkering with plot.formula

to get

plot(cbind(y1,y2) ~ x, ...)

to work.

However...

* > From: "Liaw, Andy" <andy_liaw@merck.com>
*

matplot(x, cbind(y1, y2), ...)

* > From: Barry Rowlingson <B.Rowlingson@lancaster.ac.uk>
*

xyplot(y1+y2~x,data=xyy,allow.multiple=T)

The former requires separate code for the case of multiple response variables.

The latter does provide a formula interface, but the interpretation

of the formulae is inconvenient.

For example

- if y1 is an expression containing "+"

then it would have to be protected by I() to prevent the

summands in the expression being plotted separately.

- you can't replace one of the response variables by a constant,

as this will be evaluated as a vector of length 1.

It's a lot easier with cbind() , for example

plot(cbind(z1 -zhat + bias, 0) ~ x)

gets you a plot of (z1-zhat+bias) versus x

together with a horizontal line at y=0.

The idea of using cbind() was indeed modelled on the glm() usage.

---- Adrian Baddeley, Mathematics & Statistics, University of Western Australia <http://maths.uwa.edu.au/~adrian/>______________________________________________ R-help@stat.math.ethz.ch mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help

**Next message:**Hugh Chipman: "[R] User-defined functions in rpart"**Previous message:**wolski: "[R] hist density..."

*
This archive was generated by hypermail 2.1.3
: Tue 01 Jul 2003 - 09:11:54 EST
*