arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2005.01362math.STstat.TH
收藏

类数未知数的随机块模型的不确定性量化

Uncertainty quantification in the stochastic block model with an unknown number of classes

J. van Waaij, B. J. K. Kleijn

摘要:

研究了具有未知数的不同规模的类的随机块模型的贝叶斯统计推断的频率论性质。我们配备了空间的顶点标号与先验的类的数量,并有条件地,先验的标签。类的数量可以作为顶点数量的函数增长到无穷大,这取决于图的稀疏性。我们推导出非渐近后收缩率的形式$P_{θ_{0,n}}Π_n(B_n\mid X^n)\le ε_n$,其中$X^n$是观察到的图,根据$P_{θ_{0,n}}$生成,$B_n$是$\{θ_{0, n}\}$,或者在非常稀疏的情况下,一个球周围的$θ_{0,n}$的已知程度,和$ε_n$是一个明确的收敛速度。这些结果使得可信集转换为置信集。在稀疏的情况下,可信的测试被证明是置信集。在非常稀疏的情况下,可信集被扩大以形成置信集。对于每个$n$,置信水平是明确的,作为可信水平和收敛速率的函数。类的数量之间的假设检验被认为是与后验概率的帮助下,并被证明是一致的。给出了第一和第二类误差的上界和检验功效的下界。

英文摘要:

We study the frequentist properties of Bayesian statistical inference for the stochastic block model, with an unknown number of classes of varying sizes. We equip the space of vertex labellings with a prior on the number of classes and, conditionally, a prior on the labels. The number of classes may grow to infinity as a function of the number of vertices, depending on the sparsity of the graph. We derive non-asymptotic posterior contraction rates of the form $P_{θ_{0,n}}Π_n(B_n\mid X^n)\le ε_n$, where $X^n$ is the observed graph, generated according to $P_{θ_{0,n}}$, $B_n$ is either $\{θ_{0, n}\}$ or, in the very sparse case, a ball around $θ_{0,n}$ of known extent, and $ε_n$ is an explicit rate of convergence. These results enable conversion of credible sets to confidence sets. In the sparse case, credible tests are shown to be confidence sets. In the very sparse case, credible sets are enlarged to form confidence sets. Confidence levels are explicit, for each $n$, as a function of the credible level and the rate of convergence. Hypothesis testing between the number of classes is considered with the help of posterior odds, and is shown to be consistent. Explicit upper bounds on errors of the first and second type and an explicit lower bound on the power of the tests are given.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑