--- loncom/homework/response.pm	2009/03/16 18:20:22	1.213
+++ loncom/homework/response.pm	2009/04/17 01:00:15	1.214
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # various response type definitons response definition
 #
-# $Id: response.pm,v 1.213 2009/03/16 18:20:22 bisitz Exp $
+# $Id: response.pm,v 1.214 2009/04/17 01:00:15 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -54,6 +54,7 @@ use strict;
 use Apache::lonlocal;
 use Apache::lonnet;
 use Apache::lonmaxima();
+use Apache::lonr();
 
 BEGIN {
     &Apache::lonxml::register('Apache::response',('responseparam','parameter','dataresponse','customresponse','mathresponse'));
@@ -508,7 +509,7 @@ sub start_mathresponse {
 					 'answerdisplay',$token);
 	$result.=&Apache::edit::select_arg('Algebra System:',
 					   'cas',
-					   ['maxima'],
+					   ['maxima','R'],
 					   $token);
 	$result.=&Apache::edit::text_arg('Argument Array:',
 					 'args',$token).
@@ -572,6 +573,12 @@ sub end_mathresponse {
                 $award=&Apache::lonmaxima::maxima_run($Apache::response::custom_answer[-1],$response,$args,
                                                       &Apache::lonxml::get_param('libraries',$parstack,$safeeval));
             }
+            if ($cas eq 'R') {
+                my $args = [&Apache::lonxml::get_param_var('args',$parstack,$safeeval)];
+                $award=&Apache::lonr::r_run($Apache::response::custom_answer[-1],$response,$args,
+                                            &Apache::lonxml::get_param('libraries',$parstack,$safeeval));
+            }
+
 	    if (!&Apache::inputtags::valid_award($award)) {
 		$error = $award;
 		$award = 'ERROR';