Creating Matrix from Two Arrays using Minimum of both

user_14151627 0
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Suppose I have the following (in python 3.7)

x = np.array([2,4,6])
y = np.array([3,5])

How can I obtain the output

np.array([[2, 2],
          [3, 4],
          [3, 5]])

Basically making use of the two arrays as the "axis" of my new matrix, and for each entry of the new matrix, take the min(row, col), without using any loops.

minimum python-3.x numpy python
1 Answers

The function np.meshgrid will expand both of these input variables into 2d arrays (returning a 2-element list); you can then use np.minimum to obtain element-by-element minima:

np.meshgrid(y,x)

returns:

[
  array([[3, 5],
         [3, 5],
         [3, 5]]),
  array([[2, 2],
         [4, 4],
         [6, 6]])
]

and:

np.minimum(*np.meshgrid(y,x))

returns:

array([[2, 2],
       [3, 4],
       [3, 5]])

(Using * here to expand the list into two separate arguments to np.minimum.)

user_135960370
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