R help - Apr 2008 - Help on extract paramters from fitted models

Hi, I have a question about how to extract paramters from a fitted model. I
can extract coefficients and std, but from some other statistics, I dont
know how to extract. Can anyone help?

Here it is an example:

>  coxout<-coxph(Surv(t,t.censor)~x)
> coxout
Call:
coxph(formula = Surv(t, t.censor) ~ x)

coef exp(coef) se(coef)    z    p
x 0.349      1.42    0.257 1.36 0.17

Likelihood ratio test=1.84  on 1 df, p=0.175  n= 200
> coxout$coef
        x
0.3490500
> coxout$p
NULL

Any convienent way to extract the LRT and the p value?  thank you!

	[[alternative HTML version deleted]]

See the source code of function:

getS3method("print", "coxph")

is this block:

tmp <- cbind(coef, exp(coef), se, coef/se, signif(1 -
pchisq((coef/se)^2, 1), digits - 1))


On 4/29/08, Lisa <sangwl@gmail.com> wrote:
>
> Hi, I have a question about how to extract paramters from a fitted model.
> I
> can extract coefficients and std, but from some other statistics, I dont
> know how to extract. Can anyone help?
>
> Here it is an example:
>
>
> >  coxout<-coxph(Surv(t,t.censor)~x)
>
>
> > coxout
> Call:
> coxph(formula = Surv(t, t.censor) ~ x)
>
> coef exp(coef) se(coef)    z    p
> x 0.349      1.42    0.257 1.36 0.17
>
> Likelihood ratio test=1.84  on 1 df, p=0.175  n= 200
>
> > coxout$coef
>         x
> 0.3490500
>
> > coxout$p
> NULL
>
> Any convienent way to extract the LRT and the p value?  thank you!
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

	[[alternative HTML version deleted]]

Lisa wrote:
> Hi, I have a question about how to extract paramters from a fitted model. I
> can extract coefficients and std, but from some other statistics, I dont
> know how to extract. Can anyone help?
> 
> Here it is an example:
> 
> 
>>  coxout<-coxph(Surv(t,t.censor)~x)
> 
> 
>> coxout
> Call:
> coxph(formula = Surv(t, t.censor) ~ x)
> 
> coef exp(coef) se(coef)    z    p
> x 0.349      1.42    0.257 1.36 0.17
> 
> Likelihood ratio test=1.84  on 1 df, p=0.175  n= 200
> 
>> coxout$coef
>         x
> 0.3490500
> 
>> coxout$p
> NULL
> 
> Any convienent way to extract the LRT and the p value?  thank you!
Use the summary method for coxph objects:

   summary(coxout)$logtest["test"]

   summary(coxout)$logtest["pvalue"]

Unfortunately, this is not documented in the built-in help for the 
survival package, but you can see the structure for the summary.coxph 
method by using:

   str(summary(coxout))

?summary.coxph actually points to the structure details of a coxph 
object, rather than the summary.coxph object.

HTH,

Marc Schwartz