From afb1510b929c29f4040fd7eb52f5ec0a0603eba7 Mon Sep 17 00:00:00 2001
From: Neeraj Gangwar <y.neeraj2008@gmail.com>
Date: Tue, 25 Mar 2014 11:25:15 +0530
Subject: [PATCH] added testcases for greycomatrix for angles pi/4 and 3*pi/4

---
 skimage/feature/tests/test_texture.py | 18 ++++++++++++++----
 skimage/feature/texture.py            | 12 +++++++++++-
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/skimage/feature/tests/test_texture.py b/skimage/feature/tests/test_texture.py
index e4fb6acb..ad652afc 100644
--- a/skimage/feature/tests/test_texture.py
+++ b/skimage/feature/tests/test_texture.py
@@ -11,18 +11,28 @@ class TestGLCM():
                                [2, 2, 3, 3]], dtype=np.uint8)
 
     def test_output_angles(self):
-        result = greycomatrix(self.image, [1], [0, np.pi / 2], 4)
-        assert result.shape == (4, 4, 1, 2)
+        result = greycomatrix(self.image, [1], [0, np.pi / 4, np.pi / 2, 3 * np.pi / 4], 4)
+        assert result.shape == (4, 4, 1, 4)
         expected1 = np.array([[2, 2, 1, 0],
                              [0, 2, 0, 0],
                              [0, 0, 3, 1],
                              [0, 0, 0, 1]], dtype=np.uint32)
         np.testing.assert_array_equal(result[:, :, 0, 0], expected1)
-        expected2 = np.array([[3, 0, 2, 0],
+        expected2 = np.array([[1, 1, 3, 0],
+                             [0, 1, 1, 0],
+                             [0, 0, 0, 2],
+                             [0, 0, 0, 0]], dtype=np.uint32)
+        np.testing.assert_array_equal(result[:, :, 0, 1], expected2)
+        expected3 = np.array([[3, 0, 2, 0],
                              [0, 2, 2, 0],
                              [0, 0, 1, 2],
                              [0, 0, 0, 0]], dtype=np.uint32)
-        np.testing.assert_array_equal(result[:, :, 0, 1], expected2)
+        np.testing.assert_array_equal(result[:, :, 0, 2], expected3)
+        expected4 = np.array([[2, 0, 0, 0],
+                             [1, 1, 2, 0],
+                             [0, 0, 2, 1],
+                             [0, 0, 0, 0]], dtype=np.uint32)
+        np.testing.assert_array_equal(result[:, :, 0, 3], expected4)
 
     def test_output_symmetric_1(self):
         result = greycomatrix(self.image, [1], [np.pi / 2], 4,
diff --git a/skimage/feature/texture.py b/skimage/feature/texture.py
index f9bf6c9f..a4e69518 100644
--- a/skimage/feature/texture.py
+++ b/skimage/feature/texture.py
@@ -66,17 +66,27 @@ def greycomatrix(image, distances, angles, levels=256, symmetric=False,
     ...                   [0, 0, 1, 1],
     ...                   [0, 2, 2, 2],
     ...                   [2, 2, 3, 3]], dtype=np.uint8)
-    >>> result = greycomatrix(image, [1], [0, np.pi/2], levels=4)
+    >>> result = greycomatrix(image, [1], [0, np.pi/4, np.pi/2, 3*np.pi/4], levels=4)
     >>> result[:, :, 0, 0]
     array([[2, 2, 1, 0],
            [0, 2, 0, 0],
            [0, 0, 3, 1],
            [0, 0, 0, 1]], dtype=uint32)
     >>> result[:, :, 0, 1]
+    array([[1, 1, 3, 0],
+           [0, 1, 1, 0],
+           [0, 0, 0, 2],
+           [0, 0, 0, 0]], dtype=uint32)
+    >>> result[:, :, 0, 2]
     array([[3, 0, 2, 0],
            [0, 2, 2, 0],
            [0, 0, 1, 2],
            [0, 0, 0, 0]], dtype=uint32)
+    >>> result[:, :, 0, 3]
+    array([[2, 0, 0, 0],
+           [1, 1, 2, 0],
+           [0, 0, 2, 1],
+           [0, 0, 0, 0]], dtype=uint32)
 
     """