CODEWITHSUNDEEP
rcox-regression
Triade
Triade

Reputation: 11

IDI.INF function to compare the performance of two Cox regression models

I would like to use the IDI.INF function from the survIDINRI package to the performance of two Cox regression models. For this purpose, I have used the following script:

> D=subset(Dataset, select=c("time","status","Var1","Var2","Var3", "Var4", "Var5", "Var6", "Var7", "Var8"))
>  D$status=as.numeric(D$status==2)
>  D=D[!is.na(apply(D,1,mean)),] ; dim(D)
[1] 800  10
> head(D)
> outcome=D[,c(1,2)]
> covs1<-as.matrix(D[,c(-1,-2)])
> covs0<-as.matrix(D[,c(-1,-2, -10)])
> head(outcome)
> head(covs0)
> head(covs1)
> x <-IDI.INF(outcome, covs0, covs1, t0, npert=300,npert.rand = NULL, seed1 = NULL, alpha = 0.05)

At the end, I get the following message:

Error in fitter(X, Y, strats, offset, init, control, weights = weights,  : 
  NA/NaN/Inf in foreign function call (arg 6)
In addition: Warning message:
In fitter(X, Y, strats, offset, init, control, weights = weights,  :
  Ran out of iterations and did not converge

Are there people who have experience with this IDI.INF function? Are there ways to tackle this problem?

Upvotes: 0

Views: 336

Answers (1)

Yoon Y-H
Yoon Y-H

Reputation: 1

This error message could be encountered because of weak predictive value of one variable (might be 6th variable in data.frame). You can fix this problem by removing that variable or including more number of study subjects if possible to make the prediction models stable.

Upvotes: 0

Related Questions