def diff_of_means(data_1, data_2):
"""Difference in means of two arrays."""
# The difference of means of data_1, data_2: diff
diff = np.mean(data_1) - np.mean(data_2)
return diff
# Compute difference of mean impact force from experiment: empirical_diff_means
empirical_diff_means = diff_of_means(force_a, force_b)
# Draw 10,000 permutation replicates: perm_replicates
perm_replicates = draw_perm_reps(force_a, force_b,
diff_of_means, size=10000)
# Compute p-value: p
p = np.sum(perm_replicates >= empirical_diff_means) / len(perm_replicates)
# Print the result
print('p-value =', p)
