[R] help with nomogram function

Ross Darnell r.darnell at uq.edu.au
Wed Nov 5 00:22:34 CET 2003


I have fitted a logistic regression model

> failed.lr2$call
lrm(formula = failed ~ Age + task2 + Age:task2, data = time.long, 
    na.action = na.omit)

using the Design package functions and would like to generate a
nomogram from this model.

the datadist information is generated and stored in

> ddist
                time.long$Age time.long$task2
Low:effect                 45            <NA>
Adjust to                  56       both.foam
High:effect                68            <NA>
Low:prediction             21       both.foam
High:prediction            80           right
Low                        20       both.foam
High                       80           right

Values:

time.long$task2 : both.foam left right 
> 

The model fitted and then when I try the nomgram function

> nomogram(failed.lr2)
Error in value.chk(at, i, NA, -nint, Limval, type.range = "full") : 
	variable Age does not have limits defined by datadist
> 

I get an error. The NA values in ddist seem to be the problem but I
don't understand the datadist information.

Can anyone help explain why this is failing.

Thanks

Ross Darnell

-- 

University of Queensland, Brisbane QLD 4067 AUSTRALIA
Email: <r.darnell at uq.edu.au>
Phone +61 7 3365 6087
http://www.shrs.uq.edu/shrs/school_staff/ross_darnell.html




More information about the R-help mailing list