Dear all,
I?m trying to get a output table for age and the summary of a and b, stratified
by epo as follows using summary.formula
h<-data.frame(a=sample(c("A",NA),100,replace=T),b=sample(c("B",NA),100,replace=T),age=rnorm(100,50,25),epo=sample(c("Y","N"),100,T))
library(rms)
summary.formula(epo~age+mChoice(a,b,label="test"),method="reverse",data=h,na.rm=TRUE,test=T)
Descriptive Statistics by epo
+---------+-------------------+-------------------+------------------------+
| |N |Y | Test |
| |(N=51) |(N=49) |Statistic |
+---------+-------------------+-------------------+------------------------+
|age | 43.8/53.5/74.6| 30.8/48.8/69.3|F=1.68 d.f.=1,98 P=0.198|
+---------+-------------------+-------------------+------------------------+
|test : NA| 0% (0) | 0% (0) | |
+---------+-------------------+-------------------+------------------------+
| A | 0% (0) | 0% (0) | |
+---------+-------------------+-------------------+------------------------+
| B | 0% (0) | 0% (0) | |
+---------+-------------------+-------------------+------------------------+
Digging deeper I find that
>summary(mChoice(h$a,h$b))
h$a 4 unique combinations
Frequencies of Numbers of Choices Per Observation
nchoices
1 2
30 70
Pairwise Frequencies (Diagonal Contains Marginal Frequencies)
<0 x 0 matrix>
Frequencies of All Combinations
NA A;B NA;A NA;B
30 24 23 23
Somehow this doesnt carry over into the summary.formula output...
Also, running example(mChoice) reproduces this whereby the 0% categories are
also shown.
Any ideas?
//M
