A couple of questions have discussed how to transform a matrix/table to an array/vector (see for instance here: Extract upper or lower triangular part of a numpy matrix)
But I would like to do this a very specific order, like so (matrix is symmetric):
m = np.matrix([[11, 21, 31],
[21, 22, 32],
[31, 32, 33]])
target output:
#array([11, 21, 22, 31, 32, 33])
