Hi All,
 
I use the stepAIC to select the variables of Cox ph model. But I got one
error as the following:
 
Start:  AIC= 239.32 
 Surv(SURVP, STATP) ~ AGEBMT_med + SEX + DXCODE + STAGEGRP + BSYMDX +  
    BMINVDX + PS + IPIGROUP + INITXGRP + INICHEMO + PRICHEMO +  
    PRIRESP + DXBMTMON + CON1_3 
 
Error in dropterm.default(fit, scope$drop, scale = scale, trace = max(0,
: 
        number of rows in use has changed: remove missing values?
 
 
Could you please help me with it?
 
Here is my code:
 
> whole<-read.table("E://my file/BC project/Project II/UVA and
MVA/whole.txt",header=TRUE,sep="\t")
 
>
full1<-coxph(Surv(SURVP,STATP)~AGEBMT_med+SEX+DXCODE+STAGEGRP+BSYMDX+BMI
NVDX+PS+IPIGROUP+INITXGRP+INICHEMO+PRICHEMO+PRIRESP+DXBMTMON+CON1_3,data
=whole)
> full<-stepAIC(full1)
> full
 
Thank you!
 
P.S.: The attached is the data.
 
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: whole.txt
Url:
https://stat.ethz.ch/pipermail/r-help/attachments/20060518/c74f2d0f/attachment-0003.txt