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更快的分布估计

版本 11 特别是性能上对分布估计进行了多种改善. 以下图表展示了对不同样本大小的多种分布估计时间. 测试在 Intel Xeon Processor E3-1245 v2 3.40 GHz Windows 10 系统上进行. 图底部数字显示了与版本 10 相比版本 11 的速度提高.

标准 t 分布.

In[1]:=

dist = StudentTDistribution[loc, sc, df]; ndist = StudentTDistribution[-1, 1, 2]; Table[ sample = BlockRandom[SeedRandom["MarketingExample"]; RandomVariate[ndist, n]]; Mean[Table[ First[AbsoluteTiming[EstimatedDistribution[sample, dist];]], {5}]] , {n, {10, 100, 1000}}]

Out[21]=

威布尔分布.

In[2]:=

dist = WeibullDistribution[al, be]; ndist = WeibullDistribution[3, 2]; Table[ sample = BlockRandom[SeedRandom["MarketingExample"]; RandomVariate[ndist, n]]; Mean[Table[ First[AbsoluteTiming[EstimatedDistribution[sample, dist];]], {5}]] , {n, {10, 100, 1000}}]

Out[23]=

混合二项式分布.

In[3]:=

dist = MixtureDistribution[{w1, w2}, {BinormalDistribution[{m11, m12}, {s11, s12}, \[Rho]1], BinormalDistribution[{m21, m22}, {s21, s22}, \[Rho]2]}]; ndist = MixtureDistribution[{0.3, 0.7}, {BinormalDistribution[{0, 1}, {0.5, 0.25}, 0.7], BinormalDistribution[{-0.5, 0}, {0.5, 0.25}, 0.1]}]; Table[ sample = BlockRandom[SeedRandom["MarketingExample"]; RandomVariate[ndist, n]]; Mean[Table[ First[AbsoluteTiming[ TimeConstrained[EstimatedDistribution[sample, dist];, 100]]], {5}]] , {n, {10, 100, 1000}}]

Out[117]=

多元 t 分布.

In[4]:=

dist = MultivariateTDistribution[{{m11, m12}, {m21, m22}}, n]; ndist = MultivariateTDistribution[{{1, 1/3}, {1/3, 1}}, 10]; Table[ sample = BlockRandom[SeedRandom["MarketingExample"]; RandomVariate[ndist, n]]; Mean[Table[ First[AbsoluteTiming[EstimatedDistribution[sample, dist];]], {5}]] , {n, {10, 100, 1000}}]

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