Accessing data that does not pass equality check on perfplot

Question

I'm running script that compares performance of two different functions f1 and f2. It can't pass an equality_check and raises AssertionError: Equality check failure. (f1, f2). How can I access argument and outputs of functions where it fails?

perfplot.show(
    setup=lambda n: np.random.randint(0, n, size = n),
    kernels=[f1, f2],
    n_range=[2 ** k for k in range(3, 14)],
    logx=True,
    logy=True,
    xlabel="n",
    equality_check=lambda x, y: np.array_equal(x, y)
)

Answer 1

In each step, the argument is passed to the functions f1 and f2 by perfplot, and the outputs of both functions are passed to the function specified in the parameter equality_check of perfplot.show (or perfplot.bench) function:

equality_check=foo  # foo(x, y)

In the code you provided, you defined that parameter with an anonymous function (lambda):

equality_check=lambda x, y: np.array_equal(x, y)

Check if the two functions are indeed producing the same result (for the same input), and if that result is a NumPy array with the same shape, since you are using np.array_equal(x, y).

---

If you still want to inspect those values during the process (but I recommend you check the functions f1 and f2 first), you can define the equality_check function as follows:

def foo(x, y):
    equal = np.array_equal(x, y)
    if not equal:
        print(x, y)
    return equal

That way, the outputs of f1 and f2 that cause the exception will be printed.