Firstly, we don't really need all your working. Just the problem you want solve.
However, I'm still having difficulty understanding this. > I'm observing Y[i] = (X[i]'b+e) given Y[i]>(z[i]'c+f) where e and > f are normally distributed with standard deviations s and t, > respectively, i = 1:n. I want the total of all the Y's, including those > truncated (and not observed). > (x[i]'b+e)>(z[i]c+f) > (x[i]'b-z[i]'c)>(f-e), (1) What does the tick (or single quote) mean? (2) What do you mean by "X[i]" and "observing Y[i]"? (3) Are e and f random variables, or vectors of (observed) errors? My intuitive understanding of (2), in the given context, would be that X and Y are vectors of observations. However, if e and f are random variables, wouldn't that would make Y[i] a random variable too? In which case I'm not sure what you mean by "observing". Conversely, if e and f are vectors of (observed) errors, shouldn't they be indexed (for consistency)? And in which case, there's no random component in your expressions. (4) Is lower case "x[i]" the same as upper case "X[i]", and what's "z[i]"? (5) Is the mean of e and f, zero? (6) So, you want to estimate b and c? And wouldn't that make this a parameter estimation problem? (In which case, you don't necessary need to model any distributions). > Pr{Y[i] observed} = Phi((x[i]'b-z[i]'c)/sqrt(s^2+t^2)) > where Phi is the cdf of the standard normal. This implies that "Y[i]" is a is binary (true or false) random variable. Do you mean Pr (Y <= y) where Y is a random variable and y is a possible value (from Y's sample space), that Y can be less than or equal to? You can replace y with y[i] if you want, but the principle is the same. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.