From 95d66ac5a6bd18c4f412f2a878e3e032765827f2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johannes=20Sch=C3=B6nberger?= <hannesschoenberger@gmail.com>
Date: Sat, 6 Oct 2012 21:34:41 +0200
Subject: [PATCH] Improve test coverage of find_contours

---
 skimage/measure/find_contours.py            |  2 +-
 skimage/measure/tests/test_find_contours.py | 62 ++++++++++++---------
 2 files changed, 36 insertions(+), 28 deletions(-)

diff --git a/skimage/measure/find_contours.py b/skimage/measure/find_contours.py
index 68e1d53c..eafbd523 100755
--- a/skimage/measure/find_contours.py
+++ b/skimage/measure/find_contours.py
@@ -98,7 +98,7 @@ def find_contours(array, level,
     """
     array = np.asarray(array, dtype=np.double)
     if array.ndim != 2:
-        raise RuntimeError('Only 2D arrays are supported.')
+        raise TypeError('Only 2D arrays are supported.')
     level = float(level)
     if (fully_connected not in _param_options or
        positive_orientation not in _param_options):
diff --git a/skimage/measure/tests/test_find_contours.py b/skimage/measure/tests/test_find_contours.py
index 62b39b3f..cde60e4d 100644
--- a/skimage/measure/tests/test_find_contours.py
+++ b/skimage/measure/tests/test_find_contours.py
@@ -21,34 +21,37 @@ r = np.sqrt(x**2 + y**2)
 
 
 def test_binary():
-    contours = find_contours(a, 0.5)
+    ref = [[6. ,  1.5],
+           [5. ,  1.5],
+           [4. ,  1.5],
+           [3. ,  1.5],
+           [2. ,  1.5],
+           [1.5,  2. ],
+           [1.5,  3. ],
+           [1.5,  4. ],
+           [1.5,  5. ],
+           [1.5,  6. ],
+           [1. ,  6.5],
+           [0.5,  6. ],
+           [0.5,  5. ],
+           [0.5,  4. ],
+           [0.5,  3. ],
+           [0.5,  2. ],
+           [0.5,  1. ],
+           [1. ,  0.5],
+           [2. ,  0.5],
+           [3. ,  0.5],
+           [4. ,  0.5],
+           [5. ,  0.5],
+           [6. ,  0.5],
+           [6.5,  1. ],
+           [6. ,  1.5]]
+
+    contours = find_contours(a, 0.5, positive_orientation='high')
     assert len(contours) == 1
-    assert_array_equal(contours[0],
-                     [[6. ,  1.5],
-                      [5. ,  1.5],
-                      [4. ,  1.5],
-                      [3. ,  1.5],
-                      [2. ,  1.5],
-                      [1.5,  2. ],
-                      [1.5,  3. ],
-                      [1.5,  4. ],
-                      [1.5,  5. ],
-                      [1.5,  6. ],
-                      [1. ,  6.5],
-                      [0.5,  6. ],
-                      [0.5,  5. ],
-                      [0.5,  4. ],
-                      [0.5,  3. ],
-                      [0.5,  2. ],
-                      [0.5,  1. ],
-                      [1. ,  0.5],
-                      [2. ,  0.5],
-                      [3. ,  0.5],
-                      [4. ,  0.5],
-                      [5. ,  0.5],
-                      [6. ,  0.5],
-                      [6.5,  1. ],
-                      [6. ,  1.5]])
+    assert_array_equal(contours[0][::-1], ref)
+
+
 
 
 def test_float():
@@ -70,6 +73,11 @@ def test_memory_order():
     assert len(contours) == 1
 
 
+def test_invalid_input():
+    assert_raises(ValueError, find_contours, r, 0.5, 'foo', 'bar')
+    assert_raises(TypeError, find_contours, r[..., None], 0.5)
+
+
 if __name__ == '__main__':
     from numpy.testing import run_module_suite
     run_module_suite()