Add test

src/pointwise.py

@@ -57,7 +57,7 @@ def _reciprocal_helper(v):
 
 def _abs_helper(v):
     if np.issubdtype(v.dtype, np.complexfloating):
-        raise TypeError("Argument must not be complex")
+        raise TypeError("Argument must not be complex because abs(z) is not holomorphic")
     return (np.abs(v), np.where(v == 0, np.nan, np.sign(v)))
 
 

test/test_operators/test_jacobian.py

@@ -110,6 +110,13 @@ def testAdder(space, seed, neg):
         ift.extra.check_operator(op, f, ntries=ntries)
 
 
+def testAbs(space, seed):
+    with ift.random.Context(seed):
+        f = ift.from_random(space, 'normal')
+        op = abs(ift.ScalingOperator(space, 1.))
+        ift.extra.check_operator(op, f, ntries=ntries)
+
+
 @pmp('target', [ift.RGSpace(64, distances=.789, harmonic=True),
                 ift.RGSpace([10, 10], distances=.789, harmonic=True)])
 @pmp('causal', [True, False])