TST: Add tests for np.poly()

1 files changed, 22 insertions, 0 deletions

diff --git a/numpy/lib/tests/test_polynomial.py b/numpy/lib/tests/test_polynomial.py
index 5c15941e6..8574fd813 100644
--- a/numpy/lib/tests/test_polynomial.py
+++ b/numpy/lib/tests/test_polynomial.py
@@ -89,6 +89,28 @@ class TestDocs(TestCase):
     def test_doctests(self):
         return rundocs()
 
+    def test_poly(self):
+        assert_array_almost_equal(np.poly([3, -np.sqrt(2), np.sqrt(2)]),
+                                  [1, -3, -2, 6])
+        
+        # From matlab docs
+        A = [[1, 2, 3], [4, 5, 6], [7, 8, 0]]
+        assert_array_almost_equal(np.poly(A), [1, -6, -72, -27])
+
+        # Should produce real output for perfect conjugates
+        assert_(np.isrealobj(np.poly([+1.082j, +2.613j, -2.613j, -1.082j])))
+        assert_(np.isrealobj(np.poly([0+1j, -0+-1j, 1+2j, 1-2j, 1.+3.5j, 1-3.5j])))
+        assert_(np.isrealobj(np.poly([1j, -1j, 1+2j, 1-2j, 1+3j, 1-3.j])))
+        assert_(np.isrealobj(np.poly([1j, -1j, 1+2j, 1-2j])))
+        assert_(np.isrealobj(np.poly([1j, -1j, 2j, -2j])))
+        assert_(np.isrealobj(np.poly([1j, -1j])))
+        assert_(np.isrealobj(np.poly([1, -1])))
+        
+        assert_(np.iscomplexobj(np.poly([1j, -1.0000001j])))
+
+        a = rand(100) + 1j* rand(100)
+        assert_(np.isrealobj(np.poly(np.concatenate((a, np.conjugate(a))))))
+
     def test_roots(self):
         assert_array_equal(np.roots([1, 0, 0]), [0, 0])