How to copy a smaller array to a larger array based on a value of another array?

Question

I have three arrays

a = np.array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]) #Original large array
b = np.array([4, 8, 5]) #Smaller array
c = np.array([2, 7, 9]) #Arguments

The result should look like the following

np.array([4, 4, 4, 8, 8, 8, 8, 8, 5, 5])

This means that [0, 1, 2] are replaced by 4, [3, 4, 5, 6, 7] are replaced by 8 and [8, 9] are placed by 5. Is there any numpy function/code for that?

Kanza Sheikh · Accepted Answer · 2020-07-23 18:49:01Z

1

I am not aware if such a function exists but the function down below gets the job done:

for i, element in enumerate(a):
if a[i] <= c[x]:
    a[i] = b[x]
else:
    x+=1
    a[i] = b[x]

answered Jul 23, 2020 at 18:49

Kanza Sheikh

656 bronze badges

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

1 Comment

I was specifically looking for a numpy answer. Since my array is really large then the vectorization gives much better run time compared to for loop.