[R] [FORGED] p-value=0 running log-rank test

[Rolf Turner]

This is not an R question.

Your question indicates that you really need to learn some statistics.

To answer the very last part:

 > pchisq(430,3,lower=FALSE)
[1] 7.020486e-93

And if that is not 0 to all intents and purposes, then God help us all.

cheers,

Rolf Turner

On 19/05/17 12:48, Anne Karin da Mota Borges wrote:
> Dear all,
>
> I have a question concerning the p-value. When running log-rank test I get
> a p-value = 0.
> What is it mean? Can this be true? Why aren´t there decimal points? Is
> there a way to find out the exact p-value?
>
> Here is the output:
>
>> survdiff(Surv(tempo2,status)~tphist, data=base,rho=0)
> Call:
> survdiff(formula = Surv(tempo2, status) ~ tphist, data = base,
>     rho = 0)
>
>            N Observed Expected (O-E)^2/E (O-E)^2/V
> tphist=1 513       19   40.879    11.710  9.00e+01
> tphist=2  49        4    3.892     0.003  3.27e-03
> tphist=3  23        9    1.686    31.717  3.29e+01
> tphist=4  18       15    0.543   385.172  3.91e+02
>
>  Chisq= 430  on 3 degrees of freedom, p= 0
>
> Thank you in advance.