Combine 2 arrays using numpy-CodePudding

If I have a list of points [x1, x2..xn, y1, y2..yn] how can I get [x1, y1, x2, y2..xn, yn] using numpy?

This is what I did, but idk how to continue

u = [x for idx, x in enumerate(l) if idx < len(l) / 2]
v = [x for idx, x in enumerate(l) if idx >= len(l) / 2]

CodePudding user response：

Yo could use .reshape(2, -1), combined with .T for transpose and .flatten() to interpret the array as 1d again:

import numpy as np

# create example data: x1, ..., xn = [0, ..., 4] and y1, ..., yn = [5, ..., 9]
l = list(range(10)) 
# → [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
 
z = np.array(l).reshape(2, -1).T.flatten()
# → array([0, 5, 1, 6, 2, 7, 3, 8, 4, 9])

CodePudding user response：

Numpy solution (using np.column_stack() instead of zip):

list_a = np.array([100.0, 200.0, -10.0])
list_b = [False, False, True]

print(np.column_stack((list_a, list_b)))
[[100.   0.]
 [200.   0.]
 [-10.   1.]]

Alternative:

list_a = [100.0, 200.0, -10.0]
list_b = [False, False, True]

newlist = []
for val_a, val_b in zip(list_a, list_b):
    newlist.append((val_a, val_b))
print(newlist)
[(100.0, False), (200.0, False), (-10.0, True)]

Further information: Link