Performance: Matlab vs Python

Question

I recently switched from Matlab to Python. While converting one of my lengthy codes, I was surprised to find Python being very slow. I

Answer 1

Upon further investigation I have found that using indices as indicated in the answer is still slower.

Solution: Use meshgrid

def exampleKernelA(M, x, N, y):
    """Example kernel function A"""
    # Euclidean norm function implemented using meshgrid idea.
    # Fastest
    x0, y0 = meshgrid(y[:, 0], x[:, 0])
    x1, y1 = meshgrid(y[:, 1], x[:, 1])
    # Define custom kernel here
    kernel = sqrt((x0 - y0) ** 2 + (x1 - y1) ** 2)
    return kernel

Result: Very very fast, 10 times faster than indices approach. I am getting times which are closer to C.

However: Using meshgrid with Matlab beats C and Numpy by being 10 times faster than both.

Still wondering why!