R help - Oct 2009 - Cbind() on the right-side of a formula in xYplot()

Hi,

Using the latest rms package I am able to make nice plots of model predictions 
+/- desired confidence intervals like this:

# need this
library(rms)

# setup data
d <- data.frame(x=rnorm(100), y=rnorm(100))
dd <- datadist(d)
options(datadist='dd')

# fit model
l <- ols(y ~ rcs(x), data=d)

# predict along original limits of data
l.pred <- Predict(l)

# plot of fit and conf. int.
xYplot(Cbind(yhat, lower, upper) ~ x, data=l.pred, method='filled', 
col.fill=grey(0.9), col=1, type='l')

Is there any way in which I can turn this figure on its side, by plotting x ~ 
y... something like this:

# doesn't work
xYplot(x ~ Cbind(yhat, lower, upper), data=l.pred, method='filled', 
lable.curves=FALSE, col.fill=grey(0.9), col=1, type='l')

# standard lattice, but without the fancy filled area
xyplot(x ~ yhat + lower + upper, data=l.pred, type='l', lty=c(1,2,2),
col=1)

Any suggestions? If it is not possible, then I will try and manually make the 
figure with basic lattice functions.

Cheers,
Dylan


-- 
Dylan Beaudette
Soil Resource Laboratory
http://casoilresource.lawr.ucdavis.edu/
University of California at Davis
530.754.7341

Dylan Beaudette wrote:
> Hi,
> 
> Using the latest rms package I am able to make nice plots of model
predictions
> +/- desired confidence intervals like this:
> 
> # need this
> library(rms)
> 
> # setup data
> d <- data.frame(x=rnorm(100), y=rnorm(100))
> dd <- datadist(d)
> options(datadist='dd')
> 
> # fit model
> l <- ols(y ~ rcs(x), data=d)
> 
> # predict along original limits of data
> l.pred <- Predict(l)
> 
> # plot of fit and conf. int.
> xYplot(Cbind(yhat, lower, upper) ~ x, data=l.pred, method='filled',
> col.fill=grey(0.9), col=1, type='l')
> 
> Is there any way in which I can turn this figure on its side, by plotting x
~
> y... something like this:
> 
> # doesn't work
> xYplot(x ~ Cbind(yhat, lower, upper), data=l.pred, method='filled',
> lable.curves=FALSE, col.fill=grey(0.9), col=1, type='l')
> 
> # standard lattice, but without the fancy filled area
> xyplot(x ~ yhat + lower + upper, data=l.pred, type='l',
lty=c(1,2,2), col=1)
> 
> Any suggestions? If it is not possible, then I will try and manually make
the
> figure with basic lattice functions.
> 
> Cheers,
> Dylan
> 
> 
Dylan,

Cbind is for the left hand side of the formula.  I suggest you look at 
one of the books that covers lattice graphics, or the online resources 
for lattice to customize this.  The output from Predict is suitable for 
several graphics models.

Frank

-- 
Frank E Harrell Jr   Professor and Chair           School of Medicine
                      Department of Biostatistics   Vanderbilt University