np.concatenate配列接合

concatenate((a 1,a 2,...)、axis=0)公式ドキュメント詳細

concatenate((a1, a2, ...), axis=0)

Join a sequence of arrays along an existing axis.

Parameters
----------
a1, a2, ... : sequence of array_like
    The arrays must have the same shape, except in the dimension
    corresponding to `axis` (the first, by default).
axis : int, optional
    The axis along which the arrays will be joined.  Default is 0.

Returns
-------
res : ndarray
    The concatenated array.

See Also
--------
ma.concatenate : Concatenate function that preserves input masks.
array_split : Split an array into multiple sub-arrays of equal or
              near-equal size.
split : Split array into a list of multiple sub-arrays of equal size.
hsplit : Split array into multiple sub-arrays horizontally (column wise)
vsplit : Split array into multiple sub-arrays vertically (row wise)
dsplit : Split array into multiple sub-arrays along the 3rd axis (depth).
stack : Stack a sequence of arrays along a new axis.
hstack : Stack arrays in sequence horizontally (column wise)
vstack : Stack arrays in sequence vertically (row wise)
dstack : Stack arrays in sequence depth wise (along third dimension)

2、パラメータパラメータ
接合の方向を指定する必要があります.デフォルトはaxis=0で、縦方向の接合、つまり列方向の接合です.axis=1は横方向の接合であり、行方向の接合である.
入力された配列は、接合方向axis軸に一致する形状でなければなりません.

import numpy as np

a = np.array([[1,2,3],[4,5,6]])
b = np.array([[7,8,9]])
c = np.array([[11],
              [12]])

np.concatenate((a,b), axis=0)
array([[1, 2, 3],
       [4, 5, 6],
       [7, 8, 9]])
np.concatenate((a,c), axis=1)
array([[ 1,  2,  3, 11],
       [ 4,  5,  6, 12]])