[R] problem in loop

[Seunghee Baek]

Hi R-users,
I have a problem for updating the estimates of correlation coefficient in simulation loop.
I want to get the matrix of correlation coefficients (matrix, name: est) from geese by using loop(500 times) .
I used following code to update,

nsim<-500
est<-matrix(ncol=2, nrow=nsim)
for(i in 1:nsim){

fit <- geese(x ~ trt, id=subject, data=data_gee, family=binomial, corstr="exch", scale.fix=TRUE)
.............
corr_gee<-summary(fit)$correlation[1]
se_corrgee<-summary(fit)$correlation[2]
est[i,]<-c(corr_gee, se_corrgee)
}

But, I got an error message : number of subsript in matrix does not match.

Can somebody help me? I think sumary(fit)$correlation[1] print out the name of estimates.
I guess it might cause problem to be updated in matrix.
I want to know other way to print out the estimates of correlation if it helps.

Thanks,
Becky