Python plotting from for loop

Question

How do I plot the aqr[i] values on the y-axis and the [30,60] interval on the x-axis?

I have tried the following code:

arr = np.random.randint(100, size=1000)  
arq = np.zeros(31)  

for i in range(31):
    for num in arr:
        if num == 30+i :
            arq[i] += 1
    plt.plot (arq[i])  #this line outputs an empty figure

Another version of the code I tried to get it to plot correctly is:

arr = np.random.randint(100, size=1000)  
arq = np.zeros(31) 

for i in range(31):
    for num in arr:
        for j in range (30, 61):
             if num == j+i :
            arq[i] += 1
    plt.plot (arq[i], j)

However, the above snippet of code crashes.

Ali Ismaeel · Accepted Answer · 2021-05-22 02:48:16Z

1

You are trying to plot from inside the loop, I think you need to plot the data after the construction of the arq array:

arr = np.random.randint(100, size=1000)  
arq = np.zeros(31)  

for i in range(31):
    for num in arr:
        if num == 30+i :
            arq[i] += 1

plt.rcParams["figure.figsize"] = (10,5)
plt.plot(arq,'o')

output

In this output plot 0 means 30 , 1 means 31 , etc..

answered May 22, 2021 at 2:48

Ali Ismaeel

3811 silver badge7 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

tdy · Accepted Answer · 2021-05-22 02:45:18Z

0

If I understand correctly, pull the plot() command outside the loop and plot the whole arq array at once:

np.random.seed(123)
arr = np.random.randint(100, size=1000)
arq = np.zeros(31)
for i in range(31):
    for num in arr:
        if num == 30+i:
            arq[i] += 1
plt.plot(range(30,61), arq)

Note that you can also do this with hist():

np.random.seed(123)
arr = np.random.randint(100, size=1000)
arq = np.zeros(31)
plt.hist(arr, bins=range(30, 61))

edited May 22, 2021 at 2:45

answered May 22, 2021 at 2:33

tdy

42k42 gold badges124 silver badges125 bronze badges

1 Comment

tdy Over a year ago

@Kareena you're welcome! by the way you can also use hist() to avoid looping

Collectives™ on Stack Overflow

Python plotting from for loop

2 Answers 2

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related