Re: [R] Convergence issues when using ns splines (pkg: spline) in Cox model (coxph) even when changing coxph.control

2016-03-31 Thread Therneau, Terry M., Ph.D.
Thanks to David for pointing this out. The "time dependent covariates" vignette in the survival package has a section on time dependent coefficients that talks directly about this issue. In short, the following model is simply wrong: coxph(Surv(time, status) ~ trt + prior + karno + I(karn

Re: [R] Convergence issues when using ns splines (pkg: spline) in Cox model (coxph) even when changing coxph.control

2016-03-30 Thread Göran Broström
On 2016-03-30 23:06, David Winsemius wrote: On Mar 29, 2016, at 1:47 PM, Jennifer Wu, Miss wrote: Hi, I am currently using R v3.2.3 and on Windows 10 OS 64Bit. I am having convergence issues when I use coxph with a interaction term (glarg*bca_py) and interaction term with the restricted c

Re: [R] Convergence issues when using ns splines (pkg: spline) in Cox model (coxph) even when changing coxph.control

2016-03-30 Thread David Winsemius
> On Mar 29, 2016, at 1:47 PM, Jennifer Wu, Miss > wrote: > > Hi, > > I am currently using R v3.2.3 and on Windows 10 OS 64Bit. > > I am having convergence issues when I use coxph with a interaction term > (glarg*bca_py) and interaction term with the restricted cubic spline > (glarg*bca_tim

Re: [R] Convergence issues when using ns splines (pkg: spline) in Cox model (coxph) even when changing coxph.control

2016-03-30 Thread Göran Broström
Hi Jennifer, see below. On 2016-03-29 22:47, Jennifer Wu, Miss wrote: Hi, I am currently using R v3.2.3 and on Windows 10 OS 64Bit. I am having convergence issues when I use coxph with a interaction term (glarg*bca_py) and interaction term with the restricted cubic spline (glarg*bca_time_ns).

[R] Convergence issues when using ns splines (pkg: spline) in Cox model (coxph) even when changing coxph.control

2016-03-29 Thread Jennifer Wu, Miss
Hi, I am currently using R v3.2.3 and on Windows 10 OS 64Bit. I am having convergence issues when I use coxph with a interaction term (glarg*bca_py) and interaction term with the restricted cubic spline (glarg*bca_time_ns). I use survival and spline package to create the Cox model and cubic sp