Hi Arie,
I understand what you're saying. The following excerpt out of the book
shows that F_j does not refer exclusively to categorical factors: "...the
rule does not do anything special for them, and it remains valid, in a
trivial sense, whenever any of the F_j is numeric rather than categorical
In the code below, you seem to be essentially using the random number
generator to implement a hash function. This isn't a good idea.
My impression is that pseudo-random number generation methods are
generally evaluated by whether the sequence produced from any seed
"appears" to be random. Infor
Dear list,
The following behaviour looks like a bug:
grepl("ab{,2}c", "abbbc")
# [1] TRUE
I would expect either FALSE or an "invalid regex" error.
More details can be found in the question I originally asked here:
https://stackoverflow.com/q/4664/6656269
I've also opened an issue on the TR
Removal of
ans[nas] <- NA
from the code of function 'ifelse' in R is not committed (yet). Why?
On Mon, 28/11/16, Martin Maechler wrote:
Subject: Re: [Rd] ifelse() woes ... can we agree on a ifelse2() ?
Cc: R-devel@r-project.org, maech...@stat.math.
Hello Tyler,
I rephrase my previous mail, as follows:
In your example, T_i = X1:X2:X3. Let F_j = X3. (The numerical
variables X1 and X2 are not encoded at all.) Then T_{i(j)} = X1:X2,
which in the example is dropped from the model. Hence the X3 in T_i
must be encoded by dummy variables, as indeed
