add one dimension of zero size post

_posts/2024-01-24-When-One-Dimension-is-Zero-Size.md

@@ -0,0 +1,20 @@
+---
+title: When one dimension of array is zero size
+layout: post
+---
+
+```python
+>>> from numpy import ones
+>>> ones((5, 0))
+array([], shape=(5, 0), dtype=float64)
+>>> ones((5, 0)) @ ones((5, 0)).T
+array([[0., 0., 0., 0., 0.],
+       [0., 0., 0., 0., 0.],
+       [0., 0., 0., 0., 0.],
+       [0., 0., 0., 0., 0.],
+       [0., 0., 0., 0., 0.]])
+>>> ones((3, 1)) @ ones((3, 1)).T
+array([[1., 1., 1.],
+       [1., 1., 1.],
+       [1., 1., 1.]])
+```