[R] transform a table into a matrix
Martin Maechler
maechler at stat.math.ethz.ch
Tue Jun 24 18:36:19 CEST 2008
>>>>> "JohnF" == John Fox <jfox at mcmaster.ca>
>>>>> on Tue, 24 Jun 2008 08:10:43 -0400 writes:
JohnF> Dear Maria, On 23-Jun-08, at 11:40 PM, Maria
JohnF> Gavilanez wrote:
>> Hi.
>>
>> is there a way to transform a table that has numeric and
>> categorical variables into a matrix?
JohnF> No, because all of the elements of a matrix must be
JohnF> of the same mode, but a dataframe is a data structure
JohnF> that can have heterogeneous columns. It's unclear
JohnF> from your question where the "table" is located -- in
JohnF> a file perhaps? If so, you can use read.table() to
JohnF> read the data into a dataframe.
Yes, and then possibly use data.matrix(.) to produce a numeric
matrix where the "categorical variables" have become numeric
(via their internal codes).
Martin Maechler, ETH Zurich
JohnF> I hope this helps, John
JohnF> -------------------------------------------- John
JohnF> Fox, Professor Department of Sociology McMaster
JohnF> University Hamilton ON Canada L8S 4M4 web:
JohnF> socserv.mcmaster.ca/jfox
>>
>>
>> thanks
>>
>>
>> Maria Mercedes Gavilanez Department of Biological
>> Sciences 107 Life Sciences Building Louisiana State
>> University Baton Rouge, LA 70803 (225)578-4284
>>
>> ______________________________________________
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JohnF> ______________________________________________
JohnF> R-help at r-project.org mailing list
JohnF> https://stat.ethz.ch/mailman/listinfo/r-help PLEASE
JohnF> do read the posting guide
JohnF> http://www.R-project.org/posting-guide.html and
JohnF> provide commented, minimal, self-contained,
JohnF> reproducible code.
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