[libcxx-commits] [libcxx] [libc++] Adjust some of the [rand.dist] critical values that are too strict (PR #88669)

[Matt Stephanson via libcxx-commits]

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@@ -70,8 +70,8 @@ test1()
                       3*std::exp(2*sqr(d.s())) - 6;
     assert(std::abs((mean - x_mean) / x_mean) < 0.01);
     assert(std::abs((var - x_var) / x_var) < 0.01);
-    assert(std::abs((skew - x_skew) / x_skew) < 0.05);
-    assert(std::abs((kurtosis - x_kurtosis) / x_kurtosis) < 0.25);
+    assert(std::abs((skew - x_skew) / x_skew) < 0.1);
+    assert(std::abs((kurtosis - x_kurtosis) / x_kurtosis) < 1.9);
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MattStephanson wrote:

The expected kurtosis is 0.0039, so I think that explains the loose relative tolerance.

These variates aren't normal, but just as a rough landmark, if they were, the standard deviation of the sample kurtosis would be 0.00490, so I don't think a 190% tolerance is unreasonable.

https://github.com/llvm/llvm-project/pull/88669