I have a model with quant vars only and the error message does not make sense:

(mod1 <- coxph(Surv(time=strt,time2=stp,event=(resp==1))~ +incpost+I(amt/1e5)+rate+strata(termfac),
               subset=dt<"2010-08-30", data=inc,method="efron"))
Call:
coxph(formula = Surv(time = strt, time2 = stp, event = (resp ==
    1)) ~ +incpost + I(amt/1e+05) + rate + strata(termfac), data = inc,
    subset = dt < "2010-08-30", method = "efron")


                coef exp(coef) se(coef)      z       p
incpost       0.2563     1.292  0.02479  10.34 0.0e+00
I(amt/1e+05) -0.0532     0.948  0.00487 -10.92 0.0e+00
rate         -0.0507     0.951  0.00945  -5.36 8.2e-08

Likelihood ratio test=295  on 3 df, p=0  n= 1192634

> length(mod1$xlevels)
[1] 0

# now calling survfit with just a few rows from the data
> s1 <- survfit(mod1,newdata=inc[50050:50100,],se.fit=F,individual=T,type="aa")
Error in `contrasts<-`(`*tmp*`, value = "contr.treatment") :
  contrasts can be applied only to factors with 2 or more levels

> inc[50050:50100,]
              dt      inc incpost strt stp resp rate    amt p1 matfac termfac      vol
50050 2009-02-05  0.00000    0.00    0   1    0 5.35 266833  C      5       3 14229571
50051 2009-02-06 -0.09575    0.00    1   2    0 5.35 266833  C      5       3 14229571
50052 2009-02-09 -0.03875    0.00    4   5    0 5.35 266833  C      5       3 14229571
50053 2009-02-10  0.00850    0.00    5   6    0 5.35 266833  C      5       3 14229571
50054 2009-02-11  0.00250    0.00    6   7    0 5.35 266833  C      5       3 14229571
50055 2009-02-12 -0.04725    0.00    7   8    0 5.35 266833  C      5       3 14229571
50056 2009-02-13 -0.00075    0.00    8   9    0 5.35 266833  C      5       3 14229571
50057 2009-02-16 -0.10425    0.00   11  12    0 5.35 266833  C      5       3 14229571
50058 2009-02-17 -0.10425    0.00   12  13    0 5.35 266833  C      5       3 14229571
50059 2009-02-18 -0.02925    0.00   13  14    0 5.35 266833  C      5       3 14229571
50060 2009-02-19 -0.01300    0.00   14  15    0 5.35 266833  C      5       3 14229571
50061 2009-02-20 -0.04075    0.00   15  16    0 5.35 266833  C      5       3 14229571
50062 2009-02-23 -0.03100    0.00   18  19    0 5.35 266833  C      5       3 14229571
50063 2009-02-24  0.01975    0.00   19  20    0 5.35 266833  C      5       3 14229571
50064 2009-02-25  0.13050    0.00   20  21    0 5.35 266833  C      5       3 14229571
50065 2009-02-26  0.12725    0.00   21  22    0 5.35 266833  C      5       3 14229571

... further output truncated

Please, comment if you see what's the issue.
Thank you.
Stephen


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