minor tweaks in test_offloading to allow Py(CUDA|OpenCL) arrays

tests/test_offloading.py

@@ -4,7 +4,6 @@
                        TrialFunction, Function, UnitSquareMesh,
                        SpatialCoordinate, inner, grad, dx, norm, pi, cos,
                        assemble)
-import numpy as np
 import firedrake_configuration
 from pyop2.backends.cpu import cpu_backend
 
@@ -16,6 +15,13 @@
     AVAILABLE_BACKENDS.append(cuda_backend)
 
 
+def allclose(a, b, rtol=1e-05, atol=1e-08):
+    """
+    Prefer this routine over np.allclose(...) to allow pycuda/pyopencl arrays
+    """
+    return bool(abs(a - b) < (atol + rtol * abs(b)))
+
+
 @pytest.mark.parametrize("offloading_backend", AVAILABLE_BACKENDS)
 def test_nonlinear_variational_solver(offloading_backend):
     set_offloading_backend(offloading_backend)
@@ -106,4 +112,4 @@ def test_data_manipulation_on_host(offloading_backend):
     with offloading():
         new_norm = norm(fem_soln)
 
-    np.testing.assert_allclose(kappa*old_norm, new_norm)
+    allclose(kappa*old_norm, new_norm)