How to compare function value with a constant - scipy

I'm working with Python Scipy I have the next code:
...
t = np.linspace(0, simtime, points)
def Vbooster90(t):
return np.sin(t * 2 * np.pi*F_booster + 0.5 * np.pi)
def beam(t):
return np.sign(Vrfq(t) - Vrfq(bunchwidth)) * 0.5 + 0.5
def criteria(t):
return np.sign(Vbooster90(t))
def kicker(t):
if criteria(t) > 0:
k(t)=beam(t)
else:
k(t)=0
return k(t)
I have a problem with the last function kicker(t). I want to compare the function criteria(t) with zero at each value of t, and in case if criteria(t) is higher than zero, I want to assign kicker(t) to the value of function beam(t) at the same t value. I'm new to Python and don't know syntax well.

Modify the kicker function like following.
def kicker(t):
k = 0
if criteria(t) > 0:
k = beam(t)
return k

Thanks for answers, instead of defining a function I solved it next way:
kicker = np.empty(points)
i = np.arange(points)
time = np.empty(points)
time[i] = i*simtime/points
for i in range(points):
if criteria(time[i]) > 0:
kicker[i] = beam(time[i])
else:
kicker[i] = 0

Related

How to run a formula until it meets a certain criteria?

So, I have a formula ( =INDEX(Sheet1.A1:F15,RANDBETWEEN(1,15),RANDBETWEEN(1,6)) ) that returns a random number in the sheet. But, how to run the formula until the returned number is less than or equal to 25 ?
I thought of using for..next.. but couldn't get it how to run ...
Welcome!
As #thebusybee pointed out in his comment, a macro for this task is much easier than using built-in functions. As rightly pointed out #tohuwawohu, pre-filtering the values makes things a lot easier. The macro code could be, for example, like this
Option Explicit
Function getRandValue(aValues As Variant, nTypeCriteria As Integer, dCriteriaValue As Variant) As Variant
Rem Params: aValues - array of values,
Rem nTypeCriteria - -2 less then, -1 not more, 0 equal, 1 not less, 2 more than
Rem dCriteriaValue - value to compare
Dim aTemp As Variant
Dim i As Long, j As Long, k As Long
Dim bGoodValue As Boolean
k = UBound(aValues,1)*UBound(aValues,2)
ReDim aTemp(1 To k)
k = 0
For i = 1 To UBound(aValues,1)
For j = 1 To UBound(aValues,2)
bGoodValue = False
Select Case nTypeCriteria
Case -2
bGoodValue = (aValues(i,j) < dCriteriaValue)
Case -1
bGoodValue = (aValues(i,j) <= dCriteriaValue)
Case 0
bGoodValue = (aValues(i,j) = dCriteriaValue)
Case 1
bGoodValue = (aValues(i,j) >= dCriteriaValue)
Case 2
bGoodValue = (aValues(i,j) > dCriteriaValue)
End Select
If bGoodValue Then
k = k+1
aTemp(k) = aValues(i,j)
EndIf
Next j
Next i
If k<1 Then
getRandValue = "No matching values"
ElseIf k=1 Then
getRandValue = aTemp(k)
Else
getRandValue = aTemp(Rnd()*(k-1)+1)
EndIf
End Function
Just put a call to this function in a cell in the form
=GETRANDVALUE(A1:F15;-1;25)

Name of Modules to compute sparsity

I'm writing a function that computes the sparsity of the weight matrices of the following fully connected network:
class FCN(nn.Module):
def __init__(self):
super(FCN, self).__init__()
self.fc1 = nn.Linear(input_dim, hidden_dim)
self.relu1 = nn.ReLU()
self.fc2 = nn.Linear(hidden_dim, hidden_dim)
self.relu2 = nn.ReLU()
self.fc3 = nn.Linear(hidden_dim, hidden_dim)
self.relu3 = nn.ReLU()
self.fc4 = nn.Linear(hidden_dim, output_dim)
def forward(self, x):
out = self.fc1(x)
out = self.relu1(out)
out = self.fc2(out)
out = self.relu2(out)
out = self.fc3(out)
out = self.relu3(out)
out = self.fc4(out)
return out
The function I have written is the following:
def print_layer_sparsity(model):
for name,module in model.named_modules():
if 'fc' in name:
zeros = 100. * float(torch.sum(model.name.weight == 0))
tot = float(model.name.weight.nelement())
print("Sparsity in {}.weight: {:.2f}%".format(name, zeros/tot))
But it gives me the following error:
torch.nn.modules.module.ModuleAttributeError: 'FCN' object has no attribute 'name'
It works fine when I manually enter the name of the layers (e.g.,
(model.fc1.weight == 0)
(model.fc2.weight == 0)
(model.fc3.weight == 0) ....
but I'd like to make it independent from the network. In other words, I'd like to adapt my function in a way that, given any sparse network, it prints the sparsity of every layer. Any suggestions?
Thanks!!
Try:
getattr(model, name).weight
In place of
model.name.weight
Your print_layer_sparsity function becomes:
def print_layer_sparsity(model):
for name,module in model.named_modules():
if 'fc' in name:
zeros = 100. * float(torch.sum(getattr(model, name).weight == 0))
tot = float(getattr(model, name).weight.nelement())
print("Sparsity in {}.weight: {:.2f}%".format(name, zeros/tot))
You can't do model.name because name is a str. The in-built getattr function allows you to get the member variables / attributes of an object using its name as a string.
For more information, checkout this answer.

Using zero_grad() after loss.backward(), but still receives RuntimeError: "Trying to backward through the graph a second time..."

Below is my implementation of a2c using PyTorch. Upon learning about backpropagation in PyTorch, I have known to zero_grad() the optimizer after each update iteration. However, there is still a RunTime error on second-time backpropagation.
def torchworker(number, model):
worker_env = gym.make("Taxi-v3").env
max_steps_per_episode = 2000
worker_opt = optim.Adam(lr=5e-4, params=model.parameters())
p_history = []
val_history = []
r_history = []
running_reward = 0
episode_count = 0
under = 0
start = time.time()
for i in range(2):
state = worker_env.reset()
episode_reward = 0
penalties = 0
drop = 0
print("Episode {} begins ({})".format(episode_count, number))
worker_env.render()
criterion = nn.SmoothL1Loss()
time_solve = 0
for _ in range(1, max_steps_per_episode):
#worker_env.render()
state = torch.tensor(state, dtype=torch.long)
action_probs = model.forward(state)[0]
critic_value = model.forward(state)[1]
val_history.append((state, critic_value[0]))
# Choose action
action = np.random.choice(6, p=action_probs.detach().numpy())
p_history.append(torch.log(action_probs[action]))
# Apply chosen action
state, reward, done, _ = worker_env.step(action)
r_history.append(reward)
episode_reward += reward
time_solve += 1
if reward == -10:
penalties += 1
elif reward == 20:
drop += 1
if done:
break
# Update running reward to check condition for solving
running_reward = (running_reward * (episode_count) + episode_reward) / (episode_count + 1)
# Calculate discounted returns
returns = deque(maxlen=3500)
discounted_sum = 0
for r in r_history[::-1]:
discounted_sum = r + gamma * discounted_sum
returns.appendleft(discounted_sum)
# Calculate actor losses and critic losses
loss_actor_value = 0
loss_critic_value = 0
history = zip(p_history, val_history, returns)
for log_prob, value, ret in history:
diff = ret - value[1]
loss_actor_value += -log_prob * diff
ret_tensor = torch.tensor(ret, dtype=torch.float32)
loss_critic_value += criterion(value[1], ret_tensor)
loss = loss_actor_value + 0.1 * loss_critic_value
print(loss)
# Update params
loss.backward()
worker_opt.step()
worker_opt.zero_grad()
# Log details
end = time.time()
episode_count += 1
if episode_count % 1 == 0:
worker_env.render()
if running_reward > -50: # Condition to consider the task solved
under += 1
if under > 5:
print("Solved at episode {} !".format(episode_count))
break
I believe there may be something to do with the architecture of my AC model, so I also include it here for reference.
class ActorCriticNetwork(nn.Module):
def __init__(self, num_inputs, num_hidden, num_actions):
super(ActorCriticNetwork, self).__init__()
self.embed = nn.Embedding(500, 10)
self.fc1 = nn.Linear(10, num_hidden * 2)
self.fc2 = nn.Linear(num_hidden * 2, num_hidden)
self.c = nn.Linear(num_hidden, 1)
self.fc3 = nn.Linear(num_hidden, num_hidden)
self.a = nn.Linear(num_hidden, num_actions)
def forward(self, x):
out = F.relu(self.embed(x))
out = F.relu(self.fc1(out))
out = F.relu(self.fc2(out))
critic = self.c(out)
out = F.relu(self.fc3(out.detach()))
actor = F.softmax(self.a(out), dim=-1)
return actor, critic
Would you please tell me what the mistake here is? Thank you in advance.
SOLVED: I forgot to clear the history of probabilities, action-values and rewards after iterations. It is clear why that would cause the issue, as the older elements would cause propagating through old dcgs.

Programs for printing reverse triangle patterns with * in scala

I am trying to explore Scala. I am new to Scala. This might be a simple question and searched in google to get below scenario to solve. But couldn't get answers. Instead of Scala I am getting Java related things.
My requirement to print format like below.
* * * * *
* * * *
* * *
*
Can someone suggest me how to get this format.
Thanks in advance.
Kanti
Just for the sake of illustration, here are two possible solution to the problem.
The first one is completely imperative, while the second one is more functional.
The idea is that this serves as an example to help you think how to solve problems in a programmatic way.
As many of us have already commented, if you do not understand the basic ideas behind the solution, then this code will be useless in the long term.
Here is the imperative solution, the idea is simple, we need to print n lines, each line contains n - i starts (where i is the number of the line, starting at 0). The starts are separated by an empty space.
Finally, before printing the starts, we need some padding, looking at example inputs, you can see that the padding starts at 0 and increases by 1 for each line.
def printReverseTriangle(n: Int): Unit = {
var i = 0
var padding = 0
while (i < n) {
var j = padding
while (j > 0) {
print(" ")
j -= 1
}
var k = n - i
while (k > 0) {
print("* ")
k -= 1
}
println()
i += 1
padding += 1
}
}
And here is a more functional approach.
As you can see, in this case we do not need to mutate anything, all the high level operators do that for us. And we only need to focus on the description of the solution.
def printReverseTriangle(size: Int): Unit = {
def makeReverseTriangle(size: Int): List[String] =
List.tabulate(size) { i =>
(" " * (size - i)) + ("* " * i)
}.reverse
println(makeReverseTriangle(size).mkString("\n"))
}
To add an alternative to Luis's answer, here's a recursive solution:
import scala.annotation.tailrec
def printStars(i: Int): Unit = {
#tailrec
def loop(j: Int): Unit = {
if(j > 0) {
val stars = Range(0, j).map(_ => "*").mkString(" ") // make stars
if(i == j) println(stars) // no need for spaces
else println((" " * (i - j)) + stars) // spaces before the stars
loop(j - 1)
}
}
loop(i)
}
printStars(3)
// * * *
// * *
// *
This function will take a maximum triangle size (i), and for that size until i is no longer greater than 0 it will print out the correct number of stars (and spaces), then decrement by 1.
Note: Range(0, j).map(_ => "*").mkString(" ") can be replaced with List.tabulate(j)(_ => "*").mkString(" ") per Luis's answer - I'm not sure which is faster (I've not tested it).

Improve speed on joining multiple images

What I'm trying to do is take numerous(up to 48) 1024x768 images that are color coded images(weather maps, the precip overlay) and add up the precip to fall over the course of time. When I run into non-precip I want to take a box 5x5 around the pixel in question and average the value and use that value as the value of the pixel in question.
I can do this but it takes a long time to accomplish it. I have heard numpy could improve the speed but I still haven't been able to wrap my mind around how it going to improve the speed given the sequence of events that have to take place. It seems like I would still have to do it pixel by pixel. I've included an idea of the code I'm using to accomplish this SLOWLY.
I have this actually as two separate program, one to download the images and the other does the image processing(working up toward merging the two programs in the near future, just trying to get all the bugs worked out before the merger.) Hence some of the download coding may look a little strange. I figure I could probably write the file straight to a variable but I haven't been doing it that way so I stuck with a bit longer approach.
Is there anyway of increasing the speed? I don't see anyway of avoiding pixel by pixel due to the color coding scheme in place(look at the color bar in the lower left it shows the full color scheme...I only included part of it for demo purposes in the coding below.) Some of the coding may be a bit rough since I chopped from the two programs and put the important parts in here...it shows what I'm currently doing and gives the full idea of how I'm going about doing it.
Also, if you happen to see this three to four or more days after it was posted you would need to change the date in the download link to the current date. The files are only kept on the server for 3-4 days before they are removed.
from PIL import Image
import time
import urllib
import os
pathstr = '/'
url = 'http://mag.ncep.noaa.gov/GemPakTier/MagGemPakImages/gfs/20140216/00/gfs_namer_006_1000_500_thick.gif'
urllib.urlretrieve(url,str(pathstr + '20140216006.gif'))
url = 'http://mag.ncep.noaa.gov/GemPakTier/MagGemPakImages/gfs/20140216/00/gfs_namer_012_1000_500_thick.gif'
urllib.urlretrieve(url,str(pathstr + '20140216012.gif'))
url = 'http://mag.ncep.noaa.gov/GemPakTier/MagGemPakImages/gfs/20140216/00/gfs_namer_018_1000_500_thick.gif'
urllib.urlretrieve(url,str(pathstr + '20140216018.gif'))
url = 'http://mag.ncep.noaa.gov/GemPakTier/MagGemPakImages/gfs/20140216/00/gfs_namer_024_1000_500_thick.gif'
urllib.urlretrieve(url,str(pathstr + '20140216024.gif'))
class Convert():
def __init__(self):
self.colorscale2 = [(255,255,255),(127,255,0),(0,205,0),(145,44,238),(16,78,139),
(30,144,255),(0,178,238),(0,238,238),(137,104,205),(0,139,0),
(139,0,139),(139,0,0),(205,0,0),(238,64,0),(255,127,0),(205,133,0),
(255,215,0),(238,238,0),(255,255,0),(139,71,38),(255,0,0),(0,0,255),(0,0,0)]
self.x = 0
self.y = 0
self.grid = 0
self.moist = 0
self.scan = 0
self.turn = 0
self.precip = {}
start = time.time()
for i in range(6, 30, 6):
if i < 10:
filename = '/2014021600' + str(i) + '.gif'
else:
filename = '/201402160' + str(i) + '.gif'
self.im1 = Image.open(filename).convert('RGB')
self.image = self.im1.getdata()
self.size = width, height = self.im1.size
self.coordinates = self.x,self.y = width, height
self.getprecip()
self.turn = 1
print (time.time()-start)
def getprecip(self):
for self.x in range(81, 950):
for self.y in range(29, 749):
if self.turn == 0:
self.moist = 0
else:
self.moist = self.precip[self.x,self.y]
self.coordinates = self.x,self.y
self.scan = 0
self.imagescan()
if self.turn == 0:
self.precip[self.x,self.y] = self.moist
else:
self.precip[self.x,self.y] += self.moist
def imagescan(self):
if self.image[(self.y * 1024) + self.x] == self.colorscale2[0]:
self.moist =0
self.grid -=1
elif self.image[(self.y * 1024) + self.x] == self.colorscale2[1]:
self.moist =.01
elif self.image[(self.y * 1024) + self.x] == self.colorscale2[2]:
self.moist =.1
elif self.image[(self.y * 1024) + self.x] == self.colorscale2[3]:
self.moist =.25
elif self.image[(self.y * 1024) + self.x] == self.colorscale2[4]:
self.moist =.5
#on and on through self.colorscale2[18]
if self.scan == 1:
self.grid += 1
if self.scan == 0:
x = self.x
y = self.y
self.deliso540()
self.x = x
self.y = y
def deliso540(self):
self.grid = 1
self.scan = 1
for p in range(self.x-2,self.x+2):
for q in range(self.y-2,self.y+2):
self.x = p
self.y = q
self.imagescan()
self.moist = self.moist / self.grid