--- loncom/homework/default_homework.lcpm	2009/04/17 01:00:15	1.144
+++ loncom/homework/default_homework.lcpm	2009/06/23 03:01:15	1.145
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA 
 # used by lonxml::xmlparse() as input variable $safeinit to Apache::run::run()
 #
-# $Id: default_homework.lcpm,v 1.144 2009/04/17 01:00:15 www Exp $
+# $Id: default_homework.lcpm,v 1.145 2009/06/23 03:01:15 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -434,16 +434,47 @@ sub caparesponse_check_list {
 sub cas {
     my ($system,$input,$library)=@_;
     my $output;
+    my $dump;
     if ($system eq 'maxima') {
        $output=&maxima_eval($input,$library);
     } elsif ($system eq 'R') {
-       $output=&r_eval($input,$library);
+       ($output,$dump)=&r_eval($input,$library,0);
     } else {
        $output='Error: unrecognized CAS';
     }
     return $output;
 }
 
+sub cas_hashref {
+    my ($system,$input,$library)=@_;
+    if ($system eq 'maxima') {
+       return 'Error: unsupported CAS';
+    } elsif ($system eq 'R') {
+       return &r_eval($input,$library,1);
+    } else {
+       return 'Error: unrecognized CAS';
+    }
+}
+
+#
+# cas_hashref_entry takes a list of indices and gets the entry in a hash generated by Rreturn.
+# Call: cas_hashref_entry(Rvalue, index1, index2, ...) where Rvalue is a hash returned by Rreturn.
+# Rentry will return the first scalar value it encounters (ignoring excess indices).
+# If an invalid key is given, it returns undef.
+#
+sub cas_hashref_entry {
+    return &Rentry(@_);
+}
+
+#
+# cas_hashref_array takes a list of indices and gets a column array from a hash generated by Rreturn.
+# Call: cas_hashref_array(Rvalue, index1, index2, ...) where Rvalue is a hash returned by Rreturn.
+# If an invalid key is given, it returns undef.
+#
+sub cas_hashref_array {
+    return &Rarray(@_);
+}
+
 sub tex {
     if ( $external::target eq "tex" ) {
 	return $_[0];