On Aug 20, 2011, at 8:08 PM, Salvo Mac wrote:
Thanks David
However, I tried your trick on val.surv with newdata=test['age'] but
still didn't work.
Still gives the same error message:
Error in val.surv(f.1, newdata = test1["age"], u = 10) :
dims [product 1797] do not match the length of object [2496]
In addition: Warning message:
In est.surv + S[, 1] :
longer object length is not a multiple of shorter object length
As I said (and you did not act upon):
The fundamental thing you are doing wrong for q1 is failing to
unambiguously describe the test object.
I said it was a guess. Now stop wasting our time and offer what is
needed.
--
david.
Salvo
________________________________
From: David Winsemius <dwinsem...@comcast.net>
Cc: "r-help@R-project.org" <r-help@r-project.org>
Sent: Sunday, August 21, 2011 12:55 AM
Subject: Re: [R] val.surv
On Aug 20, 2011, at 3:32 PM, Salvo Mac wrote:
Dear R-users,
I have two questions regarding validation and calibration of
Survival regression models.
1. I am trying to calibrate and validate a cox model using val.surv.
here is my code:
f.1<-cph(Surv(time,event)~age, x=T, y=T, data=train)
test1<-test[,"age"]
val.surv(f.1, newdata=data.frame(test1), u=10)
but I get an error message:
Error in val.surv(f.1, newdata = data.frame(testi), u = 10) :
dims [product 1797] do not match the length of object [2496]
In addition: Warning message:
In est.surv + S[, 1] :
longer object length is not a multiple of shorter object length
I ran the example in the r-documentation but couldn't extract
dxy from result.
What am I doing wrong?
The fundamental thing you are doing wrong for q1 is failing to
unambiguously describe the test object. I would think that if test
were a dataframe then wrapping data.frame around a vector might not
get it named correctly as 'age'. You might try newdata= test['age'].
Just a guess.
2. In validate and calibrate cph functions. If it is frailty
fit, does the the bootstrap resample clusters or just individuals
The code above appears to be dependent on the rms package. The
frailty function is part of the underlying survival package and I do
not see it mentioned in the index for Harrell's RMS text. You will
probably need to wait until Frank comes across this. He is generally
very good about correction my errors and knowledge gaps.
--
David Winsemius, MD
West Hartford, CT
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David Winsemius, MD
West Hartford, CT
______________________________________________
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
