Found "answer" to my question on MTB's INDICATOR
"C. Joseph Lu" <cjlu at ibm.stat.ncku.edu.tw> writes:
Dear R-Friends,
Sorry to bother everyone with my earlier question:
"Do we have similar R function to work like Minitab's INDICATOR?"
I found the way to make things work: e.g.,
x <- c(2,2,5,3,6,5,NA) model.matrix(~ factor(x) - 1)
factor(x)2 factor(x)3 factor(x)5 factor(x)6
1 1 0 0 0
2 1 0 0 0
3 0 0 1 0
4 0 1 0 0
5 0 0 0 1
6 0 0 1 0
attr(,"assign")
[1] 1 1 1 1
NA does not appear, fine with me.
Certainly, this is not exactly the same as Minitab's INDICATOR:
INDICATOR C2, C11-C15
C2 C11 C12 C13 C14 C15
2 1 0 0 0 0
2 1 0 0 0 0
5 ------> 0 0 0 1 0
3 0 1 0 0 0
6 0 0 0 0 1
5 0 0 0 1 0
* * * * * *
where * is missing code in Minitab.
Certainly, I still welcome any suggestion that you might have.
Looks like Minitab is creating a column of zeroes for the non-existing level "4". You can get that with
x <- c(2,2,5,3,6,5,NA) xf <- factor(x,levels=2:6) model.matrix(~xf-1)
xf2 xf3 xf4 xf5 xf6 1 1 0 0 0 0 2 1 0 0 0 0 3 0 0 0 1 0 4 0 1 0 0 0 5 0 0 0 0 1 6 0 0 0 1 0 attr(,"assign") [1] 1 1 1 1 1
O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._