R help - Feb 2008 - use classificators learned in R in "real-life", e.g. C

Hi there,
I am interested in using R for machine learning (supervised classification).
Currently, I have been investigating especially the rpart, tree, and
randomForest package, and have achieved first results.

are there any experiences, how the learned classificators could
be used in e.g. C ?
in other words, I want to "transfer" the learned predictor from R
to C-code.

for e.g. rpart, this could of course be done by hand, but, if the tree
is sufficiently complex, this is very cumbersome.
and for randomForest (which seems to work better for me), this would be 
even more complex.

maybe one way would be to call R from C, but I expect the overhead 
would be quite high - I need to perform thousands of queries

so maybe there is a convenient way to export the classificators to C?

thanks a lot,
best regards
lars

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<sich <at> gmx.de> writes:
> I am interested in using R for machine learning (supervised
classification).
> Currently, I have been investigating especially the rpart, tree, and
randomForest package, and have
> achieved first results.
> 
> are there any experiences, how the learned classificators could
> be used in e.g. C ?
> in other words, I want to "transfer" the learned predictor from R
> to C-code.
You could use dput to write the representation to a file, and read it from 
C. Parsing could be nasty, though, so I would prefer to extract the 
relevant information (e.g. fit$cptable and fit$splits in the rpart example), 
and write it to a database in numeric form with additional information if 
required. Another option could be XML (package XML), and using one of the 
many XML libraries in C(++).

Dieter

On Feb 3, 2008 2:16 PM,  <sich at gmx.de> wrote:
> Hi there,
> I am interested in using R for machine learning (supervised
classification).
> Currently, I have been investigating especially the rpart, tree, and
randomForest package, and have achieved first results.
>
> are there any experiences, how the learned classificators could
> be used in e.g. C ?
> in other words, I want to "transfer" the learned predictor from R
> to C-code.
>
I don't know of any automated way to do this for those models, but the
MARS model in the earth package can export a C-friendly version of the
prediction function. See ?format.earth for details. The bagged MARS
model in the caret package does the same (see ?format.bagEarth).

Max


-- 

Max