Flatten numpy array but also keep index of value positions?

Question

I have several 2D numpy arrays (matrix) and for each one I would like to convert it to vector containing the values of the array and a vector containing each row/column index.

Answer 1

You can simply use loops.

x = np.array([[3, 1, 4],
              [1, 5, 9],
              [2, 6, 5]])
values = []
coordinates = []
data_frame = []
for v in xrange(len(x)):
    for h in xrange(len(x[v])):
        values.append(x[v][h])
        coordinates.append((h, v))
        data_frame.append(x[v][h], h, v)
        print '%s | %s | %s' % (x[v][h], v, h)