D. R. Evans wrote:
> I have the following piece of R code:
>
> ----
>
> # next line loads a variable called "dat"
> load('/tmp/dat.R')
>
> # make a copy
> d <- dat
>
> # extract the dat$web fields for the future
> d <- subset(d, web == 'future')
>
> ----
>
> In rpy, I figured out that the equivalent starts out with:
>
> r.load('/tmp/dat.r') # creates a variable called r.dat
> d = r.dat # make a copy
>
> but I don't know what the next line should look like.
>
> I tried the obvious:
> d = r.subset(d, web == 'future')
>
> but that sure didn't go well. Neither did anything else I tried :-(
> Everything seems to cause python to complain that it doesn't know anything
> about "web".
Python should know about d["web"] but I don't think that will help.
> so could someone please tell me what that line should look like (and why)?
One option would be to start by having the d variable in python but as
an R object by turning off rpy's default object conversion. Right now,
you end up with a poor approximation of the R object, probably as a
python dictionary (my guess - I haven't checked this). If you are happy
having this as a dictionary, then this would probably do what you want:
del d['future']
Am I right in assuming the following works fine in pure R?:
d <- load('/tmp/dat.R')
d <- subset(d, web == 'future')
If so, I would suggest something like this - which avoids converting the
"d" object from R by instead keeping "d" within R:
from rpy import r
r("d <- load('/tmp/dat.R')")
r("d <- subset(d, web == 'future')")
print r("d")
And if you still want to assign it to a variable within python, perhaps
turn off the default conversion, then:
d = r("d")
Take this with a pinch of salt - I haven't actually tested these
snippets of code, I'm working from memory here.
Peter
-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems? Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/
_______________________________________________
rpy-list mailing list
rpy-list@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/rpy-list
