mstop=0 fitted and predict

[ja-thomas]

With the new possibility of mstop=0 the values of fitted(mod) and predict(mod) don't seem right.

> fitted(glmboost(speed ~ dist, data = cars, control = boost_control(mstop = 0)), type = "response")
[1] 15.4
> fitted(glmboost(speed ~ dist, data = cars, control = boost_control(mstop = 1)), type = "response")
          [,1]
 [1,] 14.72150
 [2,] 14.85396
 [3,] 14.75462
 [4,] 15.05264
 [5,] 14.95330
 [6,] 14.85396
 [7,] 14.98641
 [8,] 15.11887
...

It's clear that with mstop=0 only the same value will be repeated, but we want to have the same return type regardless of the value of mstop.

[hofnerb]

This is a duplicate of the remaining issue in #66.

The only reason I haven't fixed this is that in some circumstances we also need the scalar, i.e., when we set

mstop(mod) <- 0

I'll have to dig into that. I hope I can fix it soon. Is it important for your progress in gamboostLSS?

[ja-thomas]

Ah sorry, I've overlooked that part of the issue.

I don't think this is really needed in gamboostLSS (I've just tested it by creating the matrix by hand in the initialization and it doesn't seem do make a difference in the behaviour).