Hi 

 

I have a problem with this error, I have searched the archives and found
previous discussion about this, can I cannot understand how the explanations
apply to what I am trying to do.

 

I am trying to do Log_rank Survival analysis, I have included tables and str
command, is it a factor/integer problem? If so how do I correct this, as all
my attempt to recode the data have failed.

 

> survdiff(Surv(f2$days.alive , f2$censored)~group, data=f2)

Error in drop(.Call("La_dgesv", a, as.matrix(b), tol, PACKAGE = "base")) : 

  Lapack routine dgesv: system is exactly singular

> head(f2)

           group days.alive censored

1 PRI_CAS_5_NODU       1826        1

2 PRI_CAS_5_NODU       1488        0

3 PRI_CAS_5_NODU       1826        1

4 PRI_CAS_5_NODU       1826        1

5 PRI_CAS_5_NODU        303        0

6 PRI_CAS_5_NODU       1826        1

> str(f2)

'data.frame':   16795 obs. of  3 variables:

$ group     : Factor w/ 2 levels "PRI_CAS_5_NODU",..: 1 1 1 1 1 1 1 1 1 1
...

$ days.alive: int  1826 1488 1826 1826 303 1826 1826 971 467 1826 ...

$ censored  : int  1 0 1 1 0 1 1 0 0 1 ...

> table(f2$group)

 

PRI_CAS_5_NODU SEC_CAS_5_NODUP 

           3326           13469 

 

> table(f2$censored)

 

   0    1 

7860 8935


	[[alternative HTML version deleted]]

