I'm currently writing a code, and I have to extract from a numpy array.
For example: [[1,1] , [0.6,0.6], [0,0]]), given the condition for the extracted points [x,y] must satisfy x>=0.5 and y >= 0.5
I've tried to use numpy extract, with the condition arr[0]>=0.5 & arr[1]>=0.5 however that does not seem to work
It applied the condition on all the elements, and I just want it to apply to the points inside my array.
Thanks in advance!
You can use multiple conditions to slice an array as follows:
import numpy as np
a = np.array([[1, 1] , [0.6, 0.6], [0, 0]])
new = a[(a[:, 0] >= 0.5) & (a[:, 1] >= 0.5)]
Results:
array([[1. , 1. ],
[0.6, 0.6]])
The first condition filters on column 0 and the second condition filters on column 1. Only rows where both conditions are met will be in the results.
I would do it following way: firstly look for rows full-filling condition:
import numpy as np
a = np.array([[1,1] , [0.6,0.6], [0,0]])
rows = np.apply_along_axis(lambda x:x[0]>=0.5 and x[1]>=0.5,1,a)
then use it for indexing:
out = a[rows]
print(out)
output:
[[1. 1. ]
[0.6 0.6]]
It can be solved using python generators.
import numpy as np
p = [[1,1] , [0.6,0.6], [0,0]]
result = np.array([x for x in p if x[0]>0.5 and x[1]>0.5 ])
You can read more about generators from here.
Also you can try this:-
p = np.array(p)
result= p[np.all(p>0.5, axis=1)]
TypeError