Assume I have many numpy array:
a = ([1,2,3,4,5])
b = ([2,3,4,5,6])
c = ([3,4,5,6,7])
and I want to generate a new 2-D array:
d = ([[1,2,3,4,5],[2,3,4,5,6],[3,4,5,6,7]])
What should I code? I tried used:
d = np.concatenate((a,b),axis=0)
d = np.concatenate((d,c),axis=0)
It returns:
d = ([1,2,3,4,5,2,3,4,5,6,3,4,5,6,7])
As mentioned in the comments you could just use the np.array function:
>>> import numpy as np
>>> a = ([1,2,3,4,5])
>>> b = ([2,3,4,5,6])
>>> c = ([3,4,5,6,7])
>>> np.array([a, b, c])
array([[1, 2, 3, 4, 5],
[2, 3, 4, 5, 6],
[3, 4, 5, 6, 7]])
In the general case that you want to stack based on a "not-yet-existing" dimension, you can also use np.stack:
>>> np.stack([a, b, c], axis=0)
array([[1, 2, 3, 4, 5],
[2, 3, 4, 5, 6],
[3, 4, 5, 6, 7]])
>>> np.stack([a, b, c], axis=1) # not what you want, this is only to show what is possible
array([[1, 2, 3],
[2, 3, 4],
[3, 4, 5],
[4, 5, 6],
[5, 6, 7]])
numpy.vstack:np.vstack((a,b,c)).np.array([a,b,c])andnp.stack([a,b,c]). Both concatenate on a new dimension.