🔒 matplot histogram graph error

[west swallow]

im getting an error here and im not sure whats wrong:

import numpy as np
from numpy import random
import matplotlib.pyplot as plt
from scipy.stats import norm, binom, poisson
# Binomial Distribution
n, p = 10, 0.5  # Number of trials and probability of success
data_binomial = random.binomial(n, p, 1000)

# Plot the histogram of the binomial distribution
plt.hist(data_binomial, bins=arange(0, n + 2) - 0.5, density=True, alpha=0.6, color='b')

# Add labels and title
plt.title('Binomial Distribution (n=10, p=0.5)')
plt.xlabel('Number of Successes')
plt.ylabel('Probability')

plt.show()

there traceback is:

    plt.hist(data_binomial, bins=arange(0, n + 2) - 0.5, density=True, alpha=0.6, color='b')
                                 ^^^^^^
NameError: name 'arange' is not defined. Did you mean: 'range'?```

[fast monolith]

@west swallow

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[gray gate]

That is not related to matplotlib whatsoever, the error is exclusively about this part```py
arange(0, n + 2)

that said, `arange` is a numpy function - you have to either use `np.arange` or `from numpy import arange`

(the built-in `range` function creates an object similar to a list of python integers ; the numpy `arange` function creates a numpy array of numpy integers or numpy floats)

[west swallow]

ahhh

thats it

i forgot the np

thank u

how does that work though?

[gray gate]

"that" what exactly?

[west swallow]

thats making an array

the np.arange

[gray gate]

I'm not sure about what you mean

[west swallow]

np.arange(0, n+2)

is this making an array?

[gray gate]

do you understand what numpy is, what it does and what is its purpose?

[west swallow]

numpy is just a library right

[gray gate]

and what it does?

[west swallow]

arange is some function in the numpy library

i guess i dont?

[gray gate]

arange, not arrange

the main point of numpy is providing arrays that are more efficient than python lists and doing operations on them - it offers multiple methods to create arrays and do math operations on them

under the hood it is doing something like ```py
array = []
number = start
while number < end:
array.append(number)
number += step
return array

[west swallow]

whats the difference between an array and list?

[gray gate]

numpy arrays have a fixed shape, can only hold elements of one specific data type, and may have multiple dimensions

python lists can store any python object, you can change their length, and (although you can have nested lists), they have no real concept of dimensions

[west swallow]

when you say dimensions

what do u mean?

like x,y coordinate or something?

[gray gate]

[1, 2, 3] is a (3,) array, containing one dimensions of three elements

[[1, 2], [3, 4]] is a (2, 2) array, containing two dimensions, each of which has a length of 2

!e ```py
import numpy as np
array = np.array([
[10, 20],
[30, 40]
])

x = 0
y = 1

print(array[y, x])

[fast monolith]

@gray gate :white_check_mark: Your 3.12 eval job has completed with return code 0.

30

[west swallow]

so how is this different from a nested list in python

ah wait are the indexs in arrays like tied together somehow

so like the 1 and then 3 and the 2 and 4 are connected somehow where as in a nested list there is no such relationship

[gray gate]

!e not exactly```py
import numpy as np
array = np.array([
[10, 20],
[30, 40]
])

print(array)

take a row

print(array[0])
print(array[1])

take a column

print(array[:, 0])
print(array[:, 1])

[fast monolith]

@gray gate :white_check_mark: Your 3.12 eval job has completed with return code 0.

001 | [[10 20]
002 |  [30 40]]
003 | [10 20]
004 | [30 40]
005 | [10 30]
006 | [20 40]

[gray gate]

I recommend reading the documentation, specially the user guides, if you haven't yet

https://numpy.org/doc/stable/user/

[west swallow]

will do

as far as the bins= argument for the histogram though

how can that be an array?

shouldnt that just be an integer

[west swallow]

this was really helpful by the way

[fast monolith]

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