[R] Help with multi-response multiple factor model with varying number of factors

This is both a statistics and R question. I will give more detail if necessary. What packages of functions would help me to create a mutli-response model with multiple factors, where the number of levels for each factor is different? I have a couple hundred simulation experiments, and each exper

[R] Probit Analysis and Interval Calculations for different LD50s

I am encountering a problem with the calculation of Fieller and Delta Method confidence intervals when performing probit analysis on simulated data; my code is included below. I am testing 5 dose groups, with log doses (-0.2, -0.1, 0, 0.1, 0.2) and (1.8, 1.9, 2, 2.1, 2.2) so that the log(LD50) are