diff --git a/packages/python/examples/pyx.pl b/packages/python/examples/pyx.pl
index 0df87f002..b28e5b49f 100644
--- a/packages/python/examples/pyx.pl
+++ b/packages/python/examples/pyx.pl
@@ -3,6 +3,13 @@
 
 :- initialization(main).
 
+setup_dir :-
+	prolog_load_context(directory, Dir),
+	atom_concat(Dir,'/pyx/',Base),
+	assert(base(Base)).
+
+:- setup_dir.
+
 main :- 
 	ex(X),
 	flush_output,
@@ -10,8 +17,15 @@ main :-
 main.
 
 ex(hello_world) :-
-	c = pyx:canvas:canvas,
-	:= c:text(0, 0, 'Hello, world!'),
-	:= c:stroke(path:line(0, 0, 2, 0)),
-	c.writePDFfile('hello.pdf').
+	c := pyx:canvas:canvas,
+	:= $c:text(0, 0, 'Hello, world!'),
+	:= $c:stroke(path:line(0, 0, 2, 0)),
+	:= $c:writePDFfile('hello').
+
+ex(changebar) :-
+	g := pyx:graph:graphxy(width=8, x=graph:axis:bar),
+	atomic_concat(Source, 'minimal.dat', Data),
+	:= $g:plot(graph:data:file(Data, xname=0, y=2), [graph:style:changebar]),
+	:= $g:writePDFfile(changebar).
+
 
diff --git a/packages/python/examples/pyx/minimal.dat b/packages/python/examples/pyx/minimal.dat
new file mode 100644
index 000000000..d7b89a344
--- /dev/null
+++ b/packages/python/examples/pyx/minimal.dat
@@ -0,0 +1,12 @@
+January    -5   1
+Feburary   -4   3
+March       0   8
+April       3  13
+May         7  18
+June       10  21
+July       12  23
+August     12  23
+September   8  19
+October     4  13
+November    0   6
+December   -4   2