Implement proper constant support 9/n

src/extra.py

@@ -318,7 +318,7 @@ def _linearization_value_consistency(op, loc):
 def _check_nontrivial_constant(op, loc, tol, ntries, only_r_differentiable,
                                metric_sampling, max_combinations=np.inf):
     if isinstance(op.domain, DomainTuple):
-        return  # FIXME ?
+        return
     keys = op.domain.keys()
     combis = []
     for ll in range(1, len(keys)):

test/test_operators/test_correlated_fields.py

@@ -109,6 +109,6 @@ def testAmplitudesInvariants(sspace, N):
 
     for ampl in fa.normalized_amplitudes:
         ift.extra.check_operator(ampl, ift.from_random(ampl.domain),
-                                 ntries=3, max_combinations=5)
+                                 ntries=1, max_combinations=3)
     ift.extra.check_operator(op, ift.from_random(op.domain),
-                             ntries=3, max_combinations=5)
+                             ntries=1, max_combinations=5)