ivsacim_est: This is the main function to compute the estimator in C++
In ivsacim: Structural Additive Cumulative Intensity Models with IV

This is the main function to compute the estimator in C++

1	ivsacim_est(time, event, stime, Zc, D_status, eps_1, Zc_dot, weights)

`time`	censored event time
`event`	event indicator
`stime`	unique sorted noncensored event time
`Zc`	centered IV
`D_status`	treatment process at each noncensored event time
`eps_1`	influence function from modeling IV
`Zc_dot`	bread matrix from modeling IV
`weights`	optional weights