Loop through numpy array on indexes and apply function

Question

I'm making a correlation matrix on a timeseries, by looping over indexes of the matrix. Currently, my code is

def make_correlation_matrix(ts):
    num_regions = ts.shape[0]
    corr_mat = np.zeros((num_regions, num_regions))
    for i in range(num_regions):
        for j in range(num_regions):
            corr_mat[i,j] = np.correlate(ts[i,:], ts[j,:])
    return corr_mat

Is there a better/more efficient way to do this? Thanks.