I'm analyzing environmental data using the "NADA" R library, which relies heavily on the "survival" package.
I am dealing with left-censored data, which are nonetheless strictly positive. To deal with the positiveness I'm using a "lognormal" distribution.
As I need to use the developed model in another software I need to be able to do predictions without using the
predict command. In order to do that I'm using the following pseudo-formula (where Y is the prediction, X are the predictions and intercept, coeff and scale come from the model outcome):
Y value is different from the outcome of the
predict command using the same Xs.
What am I doing wrong?
EDIT: I found that the prediction is calculated, for the quantile of interest, using:
How is it possible to take into account also the standard error in the parameters estimates?