--- a/_test_dataset.py	Tue Jun 17 14:33:15 2008 -0400
+++ b/_test_dataset.py	Tue Jun 17 14:46:15 2008 -0400
@@ -344,6 +344,71 @@
     #        del i,example
     #* ds1 & ds2 & ds3 == ds.vstack([ds1,ds2,ds3])#????
 
+def test_subset(array,ds):
+    def test_ds(orig,ds,index):
+        i=0
+        assert isinstance(ds2,DataSet)
+        assert len(ds)==len(index)
+        for x,z,y in ds('x','z','y'):
+            assert (orig[index[i]]['x']==array[index[i]][:3]).all()
+            assert (orig[index[i]]['x']==x).all()
+            assert orig[index[i]]['y']==array[index[i]][3]
+            assert orig[index[i]]['y']==y
+            assert (orig[index[i]]['z']==array[index[i]][0:3:2]).all()
+            assert (orig[index[i]]['z']==z).all()
+            i+=1
+        del i
+        ds[0]
+        if len(ds)>2:
+            ds[:1]
+            ds[1:1]
+            ds[1:1:1]
+        if len(ds)>5:
+            ds[[1,2,3]]
+        for x in ds:
+            pass
+
+#ds[:n] returns a dataset with the n first examples.
+    ds2=ds.subset[:3]
+    test_ds(ds,ds2,index=[0,1,2])
+#     del ds2
+
+# #ds[i1:i2:s]# returns a ds with the examples i1,i1+s,...i2-s.
+#     ds2=ds.subset[1:7:2]
+#     test_ds(ds,ds2,[1,3,5])
+#     del ds2
+
+# #ds[i]
+#     ds2=ds.subset[5]
+#     assert isinstance(ds2,Example)
+#     assert have_raised("var['ds']["+str(len(ds))+"]",ds=ds)  # index not defined
+#     assert not have_raised("var['ds']["+str(len(ds)-1)+"]",ds=ds)
+#     del ds2
+
+# #ds[[i1,i2,...in]]# returns a ds with examples i1,i2,...in.
+#     ds2=ds.subset[[4,7,2,8]]
+#     test_ds(ds,ds2,[4,7,2,8])
+#     del ds2
+
+# #ds.<property># returns the value of a property associated with
+#   #the name <property>. The following properties should be supported:
+#   #    - 'description': a textual description or name for the ds
+#   #    - 'fieldtypes': a list of types (one per field)
+
+# #* ds1 | ds2 | ds3 == ds.hstack([ds1,ds2,ds3])#????
+#     #assert hstack([ds('x','y'),ds('z')])==ds
+#     #hstack([ds('z','y'),ds('x')])==ds
+#     assert have_raised2(hstack,[ds('x'),ds('x')])
+#     assert have_raised2(hstack,[ds('y','x'),ds('x')])
+#     assert not have_raised2(hstack,[ds('x'),ds('y')])
+    
+# #        i=0
+# #        for example in hstack([ds('x'),ds('y'),ds('z')]):
+# #            example==ds[i]
+# #            i+=1 
+# #        del i,example
+# #* ds1 & ds2 & ds3 == ds.vstack([ds1,ds2,ds3])#????
+
 def test_fields_fct(ds):
     #@todo, fill correctly
     assert len(ds.fields())==3
@@ -473,6 +538,7 @@
     test_iterate_over_examples(array, ds)
     test_overrides(ds)
     test_getitem(array, ds)
+    test_subset(array, ds)
     test_ds_iterator(array,ds('x','y'),ds('y','z'),ds('x','y','z'))
     test_fields_fct(ds)
 

--- a/dataset.py	Tue Jun 17 14:33:15 2008 -0400
+++ b/dataset.py	Tue Jun 17 14:46:15 2008 -0400
@@ -864,7 +864,8 @@
                 return self
             def next(self):
                 upper = self.next_example+minibatch_size
-                assert upper<=self.ds.length
+                if upper>self.ds.length:
+                    raise StopIteration
                 #minibatch = Example(self.ds._fields.keys(),
                 #                    [field[self.next_example:upper]
                 #                     for field in self.ds._fields])