@polar root
#While Loop inside of a for loop for Python.
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potent charm
Thanks, taking a look now
polar root
I appreciate it.
potent charm
just to check, is there an error you're getting or would you like help implementing the loop as you described it above
polar root
I'm just trying to get it to work as I need it. It's kinda complicated.
basically if the scatter loop is triggered I want it to run again until it's not, but I want my j to not index up for a scatter
potent charm
ah ok
in that case it might be better to use a while loop instead of a for loop
and then you can control the j variable directly
polar root
if it scatters I need it to change direction based on np.random.choice and then chang position based on the distance_to_collision equation.
That's what chatgpt tried to do. I use chatgpt when I'm stumped, but they kept doing the full loop but it also indexed up everytime.
potent charm
ok one sec, I'll show what I mean with code
polar root
That would be awesome.
If you could show me some kind of simplified example that would be great too. I don't know which is easier for you to do. Modify my code or write a few lines of how you would do it.
potent charm
# Loop through particles
j = 0
while j < n_particles:
inc_j = True
# Move particles based on direction
distance_to_collision = -np.log(np.random.rand()) / Sigma_t
position[j] += direction[j]*distance_to_collision
rand_num = np.random.uniform(low=0, high=1)
# Scatter
if rand_num < Sigma_s / Sigma_t:
inc_j = False
scatter_dir = np.random.choice([-1, 1])
direction[j] = scatter_dir
print(j)
print('we scatter')
for index in range(I_bins):
if x_index[index] < position[j] < x_index[index + 1]:
scatter_count[index, i] += 1
# Kill particles that pass the boundaries
if position[j] < x_min or position[j] > x_max:
n_particles -= 1
#distance_to_collision = x_max-np.abs(x_place)
position = np.delete(position, j)
direction = np.delete(direction, j)
cont = False
# keff_track += distance_to_collision * nu * Sigma_f
# Capture
elif Sigma_s/Sigma_t <= rand_num < (Sigma_s + Sigma_c)/Sigma_t:
n_particles -= 1
position = np.delete(position, j)
direction = np.delete(direction, j)
for index in range(I_bins):
if x_index[index] < position[j] < x_index[index + 1]:
capture_count[index] += 1
cont = False
# Fission
else:
n_particles -= 1
position = np.delete(position, j)
direction = np.delete(direction, j)
rand_num = np.random.uniform()
num_fission += 1
if rand_num < Sigma_f1/Sigma_f:
neutron_count_per_batch += 1
num_fission += 1
n_particles += 1
position = np.concatenate([
position, np.random.uniform(low=x_min, high=x_max, size=1)])
direction = np.concatenate([
direction, np.random.choice([-1, 1], size=1)])
for index in range(I_bins):
if x_index[index] < position[j] < x_index[index + 1]:
fission_count[1, index] += 1
elif Sigma_f1/Sigma_f <= rand_num < (Sigma_f1+Sigma_f2)/Sigma_f:
neutron_count_per_batch += 2
num_fission += 1
n_particles += 2
position = np.concatenate([
position, np.random.uniform(low=x_min, high=x_max, size=2)])
direction = np.concatenate([
direction, np.random.choice([-1, 1], size=2)])
for index in range(I_bins):
if x_index[index] < position[j] < x_index[index + 1]:
fission_count[2, index] += 1
else:
neutron_count_per_batch += 3
num_fission += 1
n_particles += 3
position = np.concatenate([
position, np.random.uniform(low=x_min, high=x_max, size=3)])
direction = np.concatenate([
direction, np.random.choice([-1, 1], size=3)])
for index in range(I_bins):
if x_index[index] < position[j] < x_index[index + 1]:
fission_count[3, index] += 1
if inc_j:
j += 1
Something like this is basically a for loop, but you increment j manually (see the final line), in this specific case it's slightly awkward just due to the order of the if-statements so what I've done is just made a variable (inc_j) that says if we want to increment j this loop or not. When I run this I still get the same error! so there might be an issue elsewhere
and this would just replace your code from line 59 to 154 inclusive
the only things I added were the j = 0, while j < n_particles, inc_j = True, and inv_j = False, and the final if statement to actually increment j
polar root
So I didn't realize that you had already answered Specter, because I was posting this. Sorry about that.
potent charm
haha nws
polar root
I think there is an issue elsewhere. I'm good at diagnosing those. It's just that I'm not good with the loops yet.
potent charm
can I ask how familar you are with defining your own functions? just because it might make this code a lot simpler and easier to debug
polar root
I can do it, but I have 10.5 hours to get 30 hw points so I don't have to take another class before I graduate, I feel like the code is close enough.
It's not working sitll, but I think it's closer. I will play with it some more
those are the j values along with my flag for scattering. I moved the print j back outside the if because that's not where it was supposed to be. It's 0 even if it doesn't scatter
potent charm
you only have one print(j) per loop?
polar root
It was supposed to go here
If it doesn't scatter it should index up
there should be a "we scatter" between all of the 0's
I added flags for the other events, so it's more clear what's happening
potent charm
just to check, is it intended that multiple events can occur in the same iteration?
ah I didn't indent the final if statement correctly
polar root
No, but I think I figured it out
potent charm
if you take one tab out of the if inc_j: and the line does that behave as expected>
polar root
Dude that's it.
Crap I need one last thing. I need it to also skip for #Kill particles that pass the boundaries.
Is there a break or something that I can use
potent charm
that will be exactly the same, just put a inc_j = False in that if statement
so that it looks like the scatter if statement
wait do you want to skip the rest of that iteration too?
polar root
So I had something wrong. after moving a particle. The first thing it should do is see if it has escaped the boundary
Yeah pretty much
so move particle, check to see if in bounds, if in bounds, either scatter,capture, or fission. if scattered, move and try again
potent charm
you can use continue to skip the rest of the current iteration, before you use conitnue though you should change j as needed, so maybe
j += 1
continue
``` or leave j as is depending on what you need I'm not sure of the exact contextI'm glad I could help lol
polar root
I had a hardship last fall and my professor let me do a deferred grade for this. I've been making up homeworks. It's my last class and I need a B average to graduate, which means I need a B in this class. I'm 3 points away at 77 which is 30 hw points.
I was really stuck on this
potent charm
great job getting through the work you needed in time!