Merge pull request #935 from OceanParcels/bug_kernelconcatting_random_scipy

Fixing bug when concatenating kernels with ParcelsRandom functions in scipy

Author: erikvansebille

parcels/kernel.py

@@ -37,6 +37,7 @@
 from parcels.grid import GridCode
 from parcels.kernels.advection import AdvectionRK4_3D
 from parcels.kernels.advection import AdvectionAnalytical
+import parcels.rng as ParcelsRandom  # noqa
 from parcels.tools.statuscodes import StateCode, OperationCode, ErrorCode
 from parcels.tools.statuscodes import recovery_map as recovery_base_map
 from parcels.tools.loggers import logger
@@ -116,6 +117,7 @@ def __init__(self, fieldset, ptype, pyfunc=None, funcname=None,
             try:
                 user_ctx = stack[-1][0].f_globals
                 user_ctx['math'] = globals()['math']
+                user_ctx['ParcelsRandom'] = globals()['ParcelsRandom']
                 user_ctx['random'] = globals()['random']
                 user_ctx['StateCode'] = globals()['StateCode']
                 user_ctx['OperationCode'] = globals()['OperationCode']

tests/test_kernel_language.py

@@ -294,6 +294,25 @@ class TestParticle(ptype[mode]):
     assert np.allclose(pset.p, series, atol=1e-9)
 
 
+@pytest.mark.parametrize('mode', ['scipy', 'jit'])
+@pytest.mark.parametrize('concat', [False, True])
+def test_random_kernel_concat(fieldset, mode, concat):
+    class TestParticle(ptype[mode]):
+        p = Variable('p', dtype=np.float32)
+
+    pset = ParticleSet(fieldset, pclass=TestParticle, lon=0, lat=0)
+
+    def RandomKernel(particle, fieldset, time):
+        particle.p += ParcelsRandom.uniform(0, 1)
+
+    def AddOne(particle, fieldset, time):
+        particle.p += 1.
+
+    kernels = pset.Kernel(RandomKernel)+pset.Kernel(AddOne) if concat else RandomKernel
+    pset.execute(kernels, dt=0)
+    assert pset.p > 1 if concat else pset.p < 1
+
+
 @pytest.mark.parametrize('mode', ['scipy', 'jit'])
 @pytest.mark.parametrize('c_inc', ['str', 'file'])
 def test_c_kernel(fieldset, mode, c_inc):