From 8f307c226bde17a0e1a1caf4ad98dfccc7bb0c34 Mon Sep 17 00:00:00 2001 From: Mysteryem Date: Fri, 17 Jan 2025 02:59:38 +0000 Subject: [PATCH] Core: Fix the distribution of Options.Range.triangular() (#4283) --- Options.py | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/Options.py b/Options.py index 135a1dcb..d9122d44 100644 --- a/Options.py +++ b/Options.py @@ -689,9 +689,9 @@ class Range(NumericOption): @classmethod def weighted_range(cls, text) -> Range: if text == "random-low": - return cls(cls.triangular(cls.range_start, cls.range_end, cls.range_start)) + return cls(cls.triangular(cls.range_start, cls.range_end, 0.0)) elif text == "random-high": - return cls(cls.triangular(cls.range_start, cls.range_end, cls.range_end)) + return cls(cls.triangular(cls.range_start, cls.range_end, 1.0)) elif text == "random-middle": return cls(cls.triangular(cls.range_start, cls.range_end)) elif text.startswith("random-range-"): @@ -717,11 +717,11 @@ class Range(NumericOption): f"{random_range[0]}-{random_range[1]} is outside allowed range " f"{cls.range_start}-{cls.range_end} for option {cls.__name__}") if text.startswith("random-range-low"): - return cls(cls.triangular(random_range[0], random_range[1], random_range[0])) + return cls(cls.triangular(random_range[0], random_range[1], 0.0)) elif text.startswith("random-range-middle"): return cls(cls.triangular(random_range[0], random_range[1])) elif text.startswith("random-range-high"): - return cls(cls.triangular(random_range[0], random_range[1], random_range[1])) + return cls(cls.triangular(random_range[0], random_range[1], 1.0)) else: return cls(random.randint(random_range[0], random_range[1])) @@ -739,8 +739,16 @@ class Range(NumericOption): return str(self.value) @staticmethod - def triangular(lower: int, end: int, tri: typing.Optional[int] = None) -> int: - return int(round(random.triangular(lower, end, tri), 0)) + def triangular(lower: int, end: int, tri: float = 0.5) -> int: + """ + Integer triangular distribution for `lower` inclusive to `end` inclusive. + + Expects `lower <= end` and `0.0 <= tri <= 1.0`. The result of other inputs is undefined. + """ + # Use the continuous range [lower, end + 1) to produce an integer result in [lower, end]. + # random.triangular is actually [a, b] and not [a, b), so there is a very small chance of getting exactly b even + # when a != b, so ensure the result is never more than `end`. + return min(end, math.floor(random.triangular(0.0, 1.0, tri) * (end - lower + 1) + lower)) class NamedRange(Range):