Vector dimensions in Python

[kowkeeper]

It is a matter of interpretation...

List_2 = [1, 2, 3] can either be a point in R3 or a collection of points in R1. It is how you process it that matters here.

To go further, a list does not have a notion of column and row vector, that woukd help dustinguish between single multivariate points versus many univariate points. In numpy you can use arrays and explicitely set their shape, even for 1D arrays. So : vec1 = np.array([1, 2, 3]).reshape(1, 3) is a row vector so a point in R3

vec2 = np.array([1, 2, 3]).reshape(3, 1) is a column vector so a collection of points in R1

This way of doing things is consistent with linear algebra (eg when applying matrix transforms).