Print Statement Output Absence and Unexpected Behavior in Parcels Simulation

[Cyuan-hub]

Hi, @erikvansebille. I have been troubled by the following problems for a long time, and I have tried many methods, but they still have not been solved.

1. I am running my code in a Jupyter Notebook, and I have added print statements in multiple kernel functions for debugging. However, I do not see any output from these print statements when I run the simulation.
2. In my current simulation runs, I'm observing that the values of unbeach_count do not follow the expected pattern of starting from 1 and incrementing for each particle.

For instance, here are some unbeach_count values for different particles:

• Particle 2: [0, 0, 24, 72, 120, 168, 216, 264, 281, -2147483648, -2147483648, -2147483648, ...]

• Particle 42: [0, 0, 0, 39, 87, 135, 183, 205, -2147483648, -2147483648, -2147483648, ...]

• Particle 47: [0, 0, 14, 62, 110, 158, 206, 227, -2147483648, -2147483648, -2147483648, ...]

The Parcels version I used is 2.4.2. Could you provide any insights into why these might be happening? Or is there anything I might have overlooked? Any help would be greatly appreciated.

Some of my code is below:
class CustomParticle(JITParticle):
age = Variable('age', dtype=np.float32, initial=0.)
particle_state = Variable('particle_state', dtype=np.int32, initial=0.)
unbeach_count = Variable('unbeach_count', dtype=np.int32, initial=0.)
prev_lon = Variable('prev_lon', dtype = np.float32, to_write=True, initial=attrgetter('lon'))
prev_lat = Variable('prev_lat', dtype = np.float32, to_write=True, initial=attrgetter('lat'))
countDeleteParticle = Variable('countDeleteParticle', dtype = np.int64, to_write = True)
def AdvectionRK4(particle, fieldset, time):
if particle.particle_state == 0:
(u1, v1) = fieldset.UV[time, particle.depth, particle.lat, particle.lon]
lon1_adv, lat1_adv = (particle.lon + u1*.5*particle.dt, particle.lat + v1*.5*particle.dt)
(u2, v2) = fieldset.UV[time + .5 * particle.dt, particle.depth, lat1_adv, lon1_adv]
lon2_adv, lat2_adv = (particle.lon + u2*.5*particle.dt, particle.lat + v2*.5*particle.dt)
(u3, v3) = fieldset.UV[time + .5 * particle.dt, particle.depth, lat2_adv, lon2_adv]
lon3_adv, lat3_adv = (particle.lon + u3*particle.dt, particle.lat + v3*particle.dt)
(u4, v4) = fieldset.UV[time + particle.dt, particle.depth, lat3_adv, lon3_adv]
particle.lon += = (u1 + 2*u2 + 2*u3 + u4) / 6. * particle.dt
particle.lat += (v1 + 2*v2 + 2*v3 + v4) / 6. * particle.dt
particle.particle_state = 2
def BeachTesting_Adv(particle, fieldset, time):
if particle.particle_state == 2:
part_dis_to_coast1 = fieldset.dist[time, particle.depth, particle.lat, particle.lon]
beaching_dist1 = 0.1
if part_dis_to_coast1 <= beaching_dist1:
particle.particle_state = 4
else:
particle.particle_state = 0
def UnBeaching(particle, fieldset, time):
if particle.particle_state == 4:
print("Runing Unbeaching For:")
lat_1 = particle.lat
lon_1 = particle.lon
print(lat_1)
print(lon_1)
particle.lon = particle.prev_lon
particle.lat = particle.prev_lat
print("New LatLon:")
lat_1new = particle.lat
lon_1new = particle.lon
print(lat_1new)
print(lon_1new)
particle.particle_state = 0
particle.unbeach_count += 1
def StokesDrag(particle, fieldset, time):
if particle.particle_state == 0:
(u_uss, v_uss) = fieldset.UVuss[time, particle.depth, particle.lat, particle.lon]
particle.lon += u_uss * particle.dt
particle.lat += v_uss * particle.dt
particle.particle_state = 3
def Beaching_StkDr(particle, fieldset, time):
if particle.particle_state == 3:
part_dis_to_coast2 = fieldset.dist[time, particle.depth, particle.lat, particle.lon]
beaching_dist2 = 0.1
if part_dis_to_coast2 <= beaching_dist2:
print("Particle beaching at:")
lat_beaching = particle.lat
lon_beaching = particle.lon
print(lat_beaching)
print(lon_beaching)
particle.particle_state = 1
particle.countDeleteParticle = 2
particle.delete()
else:
particle.particle_state = 0
particle.prev_lon = particle.lon
particle.prev_lat = particle.lat
Kernels= [AdvectionRK4, BeachTesting_Adv, UnBeaching, StokesDrag, Beaching_StkDr, Ageing]

[erikvansebille]

That is very likely because your outputdt is much larger than your dt.

The unbeaching count can increase on every dt, but you don't output after every dt, I suspect

[Cyuan-hub]

Oh, it actually is! My outdt is 1 day, while the dt is 30 minutes. Thanks a lot, @erikvansebille. You really pulled me out of a rut with this. I've been stuck on this for so long.

And what about the print-staments? I do not see any output from these print-statements when I run the simulation, even though I have added print-statements in kernel. Could you provide any insights into why this might be happening?

[erikvansebille]

And what about the print-staments? I do not see any output from these print-statements when I run the simulation, even though I have added print-statements in kernel. Could you provide any insights into why this might be happening?

Well, there is this old Issue #369 that may be relevant?