TST: fix ComplexWarnings by replacing .astype(float) by .real.astype(…

…float). Also adds tests that different dtypes are handled correctly in linalg/expm2. (backport of r7037, r7043)
scipy · Jan 16, 2011 · 1d06f67 · 1d06f67
1 parent 8682bd9
commit 1d06f67
Show file tree

Hide file tree

Showing 3 changed files with 18 additions and 5 deletions.
diff --git a/scipy/fftpack/tests/test_basic.py b/scipy/fftpack/tests/test_basic.py
@@ -417,17 +417,17 @@ def test_size_accuracy(self):
         for size in SMALL_COMPOSITE_SIZES + SMALL_PRIME_SIZES:
             np.random.seed(1234)
             x = np.random.rand(size, size) + 1j*np.random.rand(size, size)
-            y1 = fftn(x.astype(np.float32))
-            y2 = fftn(x.astype(np.float64)).astype(np.complex64)
+            y1 = fftn(x.real.astype(np.float32))
+            y2 = fftn(x.real.astype(np.float64)).astype(np.complex64)
 
             self.failUnless(y1.dtype == np.complex64)
             assert_array_almost_equal_nulp(y1, y2, 2000)
 
         for size in LARGE_COMPOSITE_SIZES + LARGE_PRIME_SIZES:
             np.random.seed(1234)
             x = np.random.rand(size, 3) + 1j*np.random.rand(size, 3)
-            y1 = fftn(x.astype(np.float32))
-            y2 = fftn(x.astype(np.float64)).astype(np.complex64)
+            y1 = fftn(x.real.astype(np.float32))
+            y2 = fftn(x.real.astype(np.float64)).astype(np.complex64)
 
             self.failUnless(y1.dtype == np.complex64)
             assert_array_almost_equal_nulp(y1, y2, 2000)

diff --git a/scipy/linalg/matfuncs.py b/scipy/linalg/matfuncs.py
@@ -91,7 +91,11 @@ def expm2(A):
         t = 'd'
     s,vr = eig(A)
     vri = inv(vr)
-    return dot(dot(vr,diag(exp(s))),vri).astype(t)
+    r = dot(dot(vr,diag(exp(s))),vri)
+    if t in ['f', 'd']:
+        return r.real.astype(t)
+    else:
+        return r.astype(t)
 
 def expm3(A, q=20):
     """Compute the matrix exponential using Taylor series.

diff --git a/scipy/linalg/tests/test_matfuncs.py b/scipy/linalg/tests/test_matfuncs.py
@@ -93,5 +93,14 @@ def test_zero(self):
         assert_array_almost_equal(expm2(a),[[1,0],[0,1]])
         assert_array_almost_equal(expm3(a),[[1,0],[0,1]])
 
+    def test_consistency(self):
+        a = array([[0.,1],[-1,0]])
+        assert_array_almost_equal(expm(a), expm2(a))
+        assert_array_almost_equal(expm(a), expm3(a))
+
+        a = array([[1j,1],[-1,-2j]])
+        assert_array_almost_equal(expm(a), expm2(a))
+        assert_array_almost_equal(expm(a), expm3(a))
+
 if __name__ == "__main__":
     run_module_suite()