[R] HMisc/rms package questions

[Rob James]

1) How does one capture the plots from the plsmo procedure? Simply 
inserting a routing call to a graphical device (such as jpeg, png, etc) 
and then running the plsmo procedure (and then dev.off()) does not route 
the output to the file system. 1b) Related to above, has anyone thought 
of revising the plsmo procedure to use ggplot? I'd like to capture 
several such graphs into a faceted arrangement.

2) The 2nd issue is more about communications than software. I have 
developed a model using lrm() and am using plot to display the model. 
All that is  fairly easy. However, my coauthors are used to traditional 
methods, where baseline categories are rather broadly defined (e.g. 
males, age 25-40, height 170-180cm, BP 120-140, etc) and results are 
reported as odds-ratios, not as probabilities of outcomes.

Therefore, and understandably, they are finding the graphs which arise 
from lrm->Predict->plot difficult to interpret. Specifically, in one 
graph, the adjusted to population is defined one way, and in another 
graph of the same model (displaying new predictors) there will be a new  
"adjusted to" population. Sometimes the adjusted populations are 
substantially distinct, giving rise to event rates that vary 
dramatically across graphs. This can prove challenging when trying to 
present the set of graphs as parts of a whole.  It all makes sense; it 
just adds complexity to introducing these new methods.

One strategy might be to manually define the baseline population across 
graphs; this way I could attempt to impose some content-specific 
coherence to the graphs, by selecting the baseline populations. Clearly 
this is do-able, but I have yet to see it done. I'd welcome suggestions 
and comments.

Thanks,

Rob