SciPy Recipes

See also

Joining arrays

Another way to create new arrays is to join, or concatenate, other arrays. There are several functions that make that easy. One common task is to create a two-dimensional array from its columns, and NumPy provides the column_stack() function for this specific purpose, as shown in the following example:

x = np.array([1,2,3])y = np.array([4,5,6])z = np.array([7,8,9])w = np.column_stack([x,y,z])

This produces the array:

array([[1, 4, 7],       [2, 5, 8],       [3, 6, 9]])

Notice that the arrays x, y, and z are interpreted as column vectors. The columns_stack() function always interprets its arguments as column arrays.

The concatenate() function is used to stack arrays along an arbitrary axis. The following example shows the concatenation ...