Merge 43efe15 into 40a4738

CHANGES.txt

@@ -8,12 +8,13 @@ What's new in Chaco 4.5.0
 
 Change summary since 4.4.1
 
-New features
+New features/Improvements
 
  * Added perceptual colormaps by Matteo Niccoli, Dave Green and Kenneth Moreland.
-
- * Added asynchronous_updates.py demo that shows a pattern for generating
+ * Added `asynchronous_updates.py` demo that shows a pattern for generating
    expensive plots while keeping the interface responsive (PR#170).
+ * Speeded up by 10x the data mappers of the `GridMapper` class (mapping of 2D data 
+   to/from screen space).
 
 Fixes
 
@@ -22,7 +23,7 @@ Fixes
  * Make the `alpha` attribute of scatter plots work as intended (PR#164).
  * Resume running test for empty container that has been skipped (PR#190).
  * Improved handling of missing or empty data in scatterplot (PR#210)
- * Avoid a numpy crash when using a data source of a unicode array (PR#213).
+ * Avoid a NumPy crash when using a data source of a unicode array (PR#213).
  * PanTool with `restrict_to_data` selected works with empty data sources
    (PR#215).
  * RangeSelection properly clips bounds when leaving selection area (PR#217).

chaco/grid_mapper.py

@@ -7,7 +7,7 @@
 from contextlib import contextmanager
 
 # Major library imports
-from numpy import transpose
+from numpy import column_stack, transpose
 
 # Enthought library imports
 from traits.api import Bool, DelegatesTo, Instance, Float, Property
@@ -119,7 +119,8 @@ def map_screen(self, data_pts):
         xs, ys = transpose(data_pts)
         screen_xs = self._xmapper.map_screen(xs)
         screen_ys = self._ymapper.map_screen(ys)
-        return zip(screen_xs, screen_ys)
+        screen_pts = column_stack([screen_xs, screen_ys])
+        return screen_pts
 
     def map_data(self, screen_pts):
         """ map_data(screen_pts) -> data_vals
@@ -129,7 +130,8 @@ def map_data(self, screen_pts):
         screen_xs, screen_ys = transpose(screen_pts)
         xs = self._xmapper.map_data(screen_xs)
         ys = self._ymapper.map_data(screen_ys)
-        return zip(xs, ys)
+        data_pts = column_stack([xs, ys])
+        return data_pts
 
     def map_data_array(self, screen_pts):
         return self.map_data(screen_pts)

chaco/tests/grid_mapper_test_case.py

@@ -7,20 +7,48 @@
 
 class GridMapperTestCase(unittest.TestCase):
 
-    def test_basic(self):
-        x_ary = array([5.0, 6.0, 7.0, 8.0, 9.0, 10.0])
-        y_ary = array([1.0, 1.0, 2.0, 2.0, 3.0, 3.0])
-        ds = GridDataSource(xdata=x_ary, ydata=y_ary)
+    def setUp(self):
+        self.x_ary = array([5.0, 6.0, 7.0, 8.0, 9.0, 10.0])
+        self.y_ary = array([1.0, 1.0, 2.0, 2.0, 3.0, 3.0])
+        ds = GridDataSource(xdata=self.x_ary, ydata=self.y_ary)
         r = DataRange2D(ds)
-        mapper = GridMapper(range=r)
-        mapper.x_low_pos=50
-        mapper.x_high_pos=100
-        mapper.y_low_pos=0
-        mapper.y_high_pos=10
-        result = mapper.map_screen(transpose((x_ary, y_ary)))
+        self.mapper = GridMapper(range=r)
+
+    def test_basic(self):
+        self.mapper.x_low_pos=50
+        self.mapper.x_high_pos=100
+        self.mapper.y_low_pos=0
+        self.mapper.y_high_pos=10
+        result = self.mapper.map_screen(transpose((self.x_ary, self.y_ary)))
         assert_equal(result, [(50,0), (60,0), (70,5),
                               (80,5), (90,10), (100,10)])
 
+    def test_map_screen_scalar(self):
+        self.mapper.x_low_pos=50
+        self.mapper.x_high_pos=100
+        self.mapper.y_low_pos=0
+        self.mapper.y_high_pos=10
+        result = self.mapper.map_screen(transpose((6.0, 1.0)))
+        assert_equal(result, [[60, 0]])
+
+    def test_map_data(self):
+        self.mapper.x_low_pos=50
+        self.mapper.x_high_pos=100
+        self.mapper.y_low_pos=0
+        self.mapper.y_high_pos=10
+        screen_ary = array([(50,0), (60,0), (70,5), (80,5), (90,10), (100,10)])
+        result = self.mapper.map_data(screen_ary)
+        assert_equal(result, transpose((self.x_ary, self.y_ary)))
+
+    def test_map_data_scalar(self):
+        self.mapper.x_low_pos=50
+        self.mapper.x_high_pos=100
+        self.mapper.y_low_pos=0
+        self.mapper.y_high_pos=10
+        screen_ary = (60, 0)
+        result = self.mapper.map_data(screen_ary)
+        assert_equal(result, [[6.0, 1.0]])
+
 
 if __name__ == '__main__':
     import nose