def time()

in torchbeast/core/prof.py [0:0]

• 12 lines of code
• 1 McCabe index (conditional complexity)

    def time(self, name):
        """Save an update for event `name`.

        Nerd alarm: We could just store a
            collections.defaultdict(list)
        and compute means and standard deviations at the end. But thanks to the
        clever math in Sutton-Barto
        (http://www.incompleteideas.net/book/first/ebook/node19.html) and
        https://math.stackexchange.com/a/103025/5051 we can update both the
        means and the stds online. O(1) FTW!
        """
        now = timeit.default_timer()
        x = now - self.last_time
        self.last_time = now

        n = self._counts[name]

        mean = self._means[name] + (x - self._means[name]) / (n + 1)
        var = (
            n * self._vars[name] + n * (self._means[name] - mean) ** 2 + (x - mean) ** 2
        ) / (n + 1)

        self._means[name] = mean
        self._vars[name] = var
        self._counts[name] += 1