Sorry this has taken so long to get back to you, I have been out of the office
a lot recently.
The documentation for read.table suggests that since an as.ordered function
exists, that you could just use "ordered" as a column class, but I don't know
how well that works in practice. In general I think it is better to let
read.table create regular factors, then change them to ordered factors by hand
afterwards. For regular factors, the default ordering (since order does not
matter) is alphabetical by factor level. This is not usually the correct
ordering for ordered factors and read.table has no way of knowing what the
proper order should be. When you change them by hand you can specify the
ordering rather than taking the usually wrong default.
--
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
[EMAIL PROTECTED]
(801) 408-8111
________________________________
From: Birgit Lemcke [mailto:[EMAIL PROTECTED]
Sent: Friday, August 24, 2007 2:13 AM
To: Greg Snow
Cc: R Hilfe
Subject: Re: [R] ordered factors in data.frame
Thanks a lot Greg for your help.
This works fine.
Normally I use a vector to set the classes for the variables:
Classe<-cclasses <- c(rep("factor", 14), rep("numeric", 4))
Table1<-read.table("Name", sep = ";", colClasses = Classe)
How can I implement to set colClasses as ordererd factor here.
Following works not:
Classe<-cclasses <- c(rep("factor", 61), rep("numeric", 14),
rep("odered", 10))
Thanks in advance
Birgit
Am 23.08.2007 um 21:21 schrieb Greg Snow:
The attach function only attachs a copy of the data (changes to
the data don't show up in the attached copy). Also you need to tell R what to
do with the result of as.ordered (where to save it).
Try something like:
table$V3 <- as.ordered(table$V3)
Or
table <- transform(table, V3=as.ordered(V3) )
Hope this helps,
--
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
[EMAIL PROTECTED]
(801) 408-8111
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Birgit Lemcke
Sent: Thursday, August 23, 2007 11:28 AM
To: R Hilfe
Subject: [R] ordered factors in data.frame
Hello I need a tiny peace of help. (PPC Mac Os X
10.4.10; R 2.5.1)
I have a data.frame with numeric and factor variables.
I would like to convert same of the factors to ordered
factors.
I tried with:
attach (table)
as.ordered (V3)
but this gives me only the V3 Vector as ordred back but
in
the data.frame (str(Table)) it is still not ordered.
How can I do that?
Thanks for your help.
I am still a beginner.
Greetings
Birgit
Now I would like to
Birgit Lemcke
Institut für Systematische Botanik
Zollikerstrasse 107
CH-8008 Zürich
Switzerland
Ph: +41 (0)44 634 8351
[EMAIL PROTECTED]
[[alternative HTML version deleted]]
Birgit Lemcke
Institut für Systematische Botanik
Zollikerstrasse 107
CH-8008 Zürich
Switzerland
Ph: +41 (0)44 634 8351
[EMAIL PROTECTED]
[[alternative HTML version deleted]]
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