Added unit test.

ianthomas23 · ianthomas23 · commit d55d861d4275 · 2012-06-08T09:55:29.000+01:00
diff --git a/lib/matplotlib/tests/test_triangulation.py b/lib/matplotlib/tests/test_triangulation.py
@@ -0,0 +1,96 @@
+import numpy as np
+import matplotlib.tri as mtri
+import matplotlib.delaunay as mdel
+from nose.tools import assert_equal
+from numpy.testing import assert_array_equal, assert_array_almost_equal
+
+def test_delaunay():
+    # No duplicate points.
+    x = [0,1,1,0]
+    y = [0,0,1,1]
+    npoints = 4
+    ntriangles = 2
+    nedges = 5
+
+    # Without duplicate points, mpl calls delaunay triangulation and
+    # does not modify it.
+    mpl_triang = mtri.Triangulation(x,y)
+    del_triang = mdel.Triangulation(x,y)
+
+    # Points - floating point.
+    assert_array_almost_equal(mpl_triang.x, x)
+    assert_array_almost_equal(mpl_triang.x, del_triang.x)
+    assert_array_almost_equal(mpl_triang.y, y)
+    assert_array_almost_equal(mpl_triang.y, del_triang.y)
+
+    # Triangles - integers.
+    assert_equal(len(mpl_triang.triangles), ntriangles)
+    assert_equal(np.min(mpl_triang.triangles), 0)
+    assert_equal(np.max(mpl_triang.triangles), npoints-1)
+    assert_array_equal(mpl_triang.triangles, del_triang.triangle_nodes)
+
+    # Edges - integers.
+    assert_equal(len(mpl_triang.edges), nedges)
+    assert_equal(np.min(mpl_triang.edges), 0)
+    assert_equal(np.max(mpl_triang.edges), npoints-1)
+    assert_array_equal(mpl_triang.edges, del_triang.edge_db)
+
+def test_delaunay_duplicate_points():
+    # Issue 838.
+    import warnings
+
+    # Index 2 is the same as index 0.
+    x = [0,1,0,1,0]
+    y = [0,0,0,1,1]
+    duplicate_index = 2
+    npoints = 4        # Number of non-duplicate points.
+    nduplicates = 1
+    ntriangles = 2
+    nedges = 5
+
+    # With duplicate points, mpl calls delaunay triangulation but
+    # modified returned arrays.
+    warnings.simplefilter("ignore")   # Ignore DuplicatePointWarning.
+    mpl_triang = mtri.Triangulation(x,y)
+    del_triang = mdel.Triangulation(x,y)
+    warnings.resetwarnings()
+
+    # Points - floating point.
+    assert_equal(len(mpl_triang.x), npoints + nduplicates)
+    assert_equal(len(del_triang.x), npoints)
+    assert_array_almost_equal(mpl_triang.x, x)
+    assert_array_almost_equal(del_triang.x[:duplicate_index], x[:duplicate_index])
+    assert_array_almost_equal(del_triang.x[duplicate_index:], x[duplicate_index+1:])
+
+    assert_equal(len(mpl_triang.y), npoints + nduplicates)
+    assert_equal(len(del_triang.y), npoints)
+    assert_array_almost_equal(mpl_triang.y, y)
+    assert_array_almost_equal(del_triang.y[:duplicate_index], y[:duplicate_index])
+    assert_array_almost_equal(del_triang.y[duplicate_index:], y[duplicate_index+1:])
+
+    # Triangles - integers.
+    assert_equal(len(mpl_triang.triangles), ntriangles)
+    assert_equal(np.min(mpl_triang.triangles), 0)
+    assert_equal(np.max(mpl_triang.triangles), npoints-1 + nduplicates)
+    assert_equal(len(del_triang.triangle_nodes), ntriangles)
+    assert_equal(np.min(del_triang.triangle_nodes), 0)
+    assert_equal(np.max(del_triang.triangle_nodes), npoints-1)
+    # Convert mpl triangle point indices to delaunay's.
+    converted_indices = np.where(mpl_triang.triangles > duplicate_index,
+                                 mpl_triang.triangles - nduplicates,
+                                 mpl_triang.triangles)
+    assert_array_equal(del_triang.triangle_nodes, converted_indices)
+
+    # Edges - integers.
+    assert_equal(len(mpl_triang.edges), nedges)
+    assert_equal(np.min(mpl_triang.edges), 0)
+    assert_equal(np.max(mpl_triang.edges), npoints-1 + nduplicates)
+    assert_equal(len(del_triang.edge_db), nedges)
+    assert_equal(np.min(del_triang.edge_db), 0)
+    assert_equal(np.max(del_triang.edge_db), npoints-1)
+    # Convert mpl edge point indices to delaunay's.
+    converted_indices = np.where(mpl_triang.edges > duplicate_index,
+                                 mpl_triang.edges - nduplicates,
+                                 mpl_triang.edges)
+    assert_array_equal(del_triang.edge_db, converted_indices)
+
