I have a 5x5 ones matrix:
[[1. 1. 1. 1. 1.]
[1. 1. 1. 1. 1.]
[1. 1. 1. 1. 1.]
[1. 1. 1. 1. 1.]
[1. 1. 1. 1. 1.]]
and I want to fill it with this one dimension array:
[0.72222515 1.25003225 0.11767353 0.16121767 0.27926356 0.78412963
0.08371721 1.77536532 1.67636045 0.55364691]
like:
[[0.72222515 1.25003225 0.11767353 0.16121767 0.27926356]
[0.78412963 0.08371721 1.77536532 1.67636045 0.55364691]
[[0.72222515 1.25003225 0.11767353 0.16121767 0.27926356]
[0.78412963 0.08371721 1.77536532 1.67636045 0.55364691]
[[0.72222515 1.25003225 0.11767353 0.16121767 0.27926356]
What can I do in python?
CodePudding user response:
Instead of filling an existing array, we could make a new array with the desired layout.
In [129]: arr = np.arange(10)
repeat
is a fast way of making multiple copies. And since you are "filling" two rows at a time, let's apply the repeat to the 1d array - expanded to 2d:
In [132]: arr[None,:].repeat(3,0)
Out[132]:
array([[0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]])
Then reshape to the desired shape:
In [133]: arr[None,:].repeat(3,0).reshape(6,5)
Out[133]:
array([[0, 1, 2, 3, 4],
[5, 6, 7, 8, 9],
[0, 1, 2, 3, 4],
[5, 6, 7, 8, 9],
[0, 1, 2, 3, 4],
[5, 6, 7, 8, 9]])
And use slicing to get rid of the extra row:
In [134]: arr[None,:].repeat(3,0).reshape(6,5)[:5,:]
Out[134]:
array([[0, 1, 2, 3, 4],
[5, 6, 7, 8, 9],
[0, 1, 2, 3, 4],
[5, 6, 7, 8, 9],
[0, 1, 2, 3, 4]])
Even if we go the fill route, it's easiest to work with a 10 column ones
:
In [135]: new = np.ones((3,10)); new[:] = arr
In [136]: new
Out[136]:
array([[0., 1., 2., 3., 4., 5., 6., 7., 8., 9.],
[0., 1., 2., 3., 4., 5., 6., 7., 8., 9.],
[0., 1., 2., 3., 4., 5., 6., 7., 8., 9.]])
In [137]: new.reshape(-1,5)[:5,:]
Out[137]:
array([[0., 1., 2., 3., 4.],
[5., 6., 7., 8., 9.],
[0., 1., 2., 3., 4.],
[5., 6., 7., 8., 9.],
[0., 1., 2., 3., 4.]])
CodePudding user response:
Probably we can do that with a loop, like this... Not sure if this is the best way...
import numpy as np
arr1 = np.ones((5,5))
arr2 = np.array([1,2,3,4,5,6,7,8,9,10])
arr2 = np.reshape(arr2, (-1, 5))
for i in range(0,len(arr1)):
if i % 2 == 0:
arr1[i] = arr2[0]
else:
arr1[i] = arr2[1]
# Output of arr1
array([[ 1., 2., 3., 4., 5.],
[ 6., 7., 8., 9., 10.],
[ 1., 2., 3., 4., 5.],
[ 6., 7., 8., 9., 10.],
[ 1., 2., 3., 4., 5.]])