arXiv subjects

Tilo Wiklund

Publications and source records attributed to Tilo Wiklund.

5 recordsLinked to original sources

arXiv2023

Another look at binomial and related distributions exceeding values close to their centre

We generalise the known fact that for binomial $X_{n,k} \sim \mathrm{Bin}(n, k/n)$ one has $\inf_{k>1,n} \mathrm{P}(X_{n,k} \geq k) \geq \lim_{k \to 1+}\mathrm{P}(X_{2,k} \geq k) = 1/4$ to cover probabilities of exceeding a constant shift away from the mean. The proof is very short and the theorem yields the original result as a special case, as well as proving that an analogous result holds for the Poisson distribution. We furthermore prove a similar property holds for the family of beta distributions near their mode. Thanks to the connection between Binomial and Beta distributions, this allows us to shed some further light on the original result regarding Binomial probabilities.

math.PR↗

arXiv2020

Scalable Multivariate Histograms

We give a distributed variant of an adaptive histogram estimation procedure previously developed by the first author. The procedure is based on regular pavings and is known to have numerous appealing statistical and arithmetical properties. The distributed version makes it possible to process data sets significantly bigger than previously. We provide prototype implementation under a permissive license.

stat.CO↗

arXiv2020

Self-driving car safety quantification via component-level analysis

In this paper, we present a rigorous modular statistical approach for arguing safety or its insufficiency of an autonomous vehicle through a concrete illustrative example. The methodology relies on making appropriate quantitative studies of the performance of constituent components. We explain the importance of sufficient and necessary conditions at the component level for the overall safety of the vehicle as well as the cost-saving benefits of the approach. A simple concrete automated braking example studied illustrates how separate perception system and operational design domain statistical analyses can be used to prove or disprove safety at the vehicle level.

stat.AP↗

arXiv2020

Information in additional observations of a non-parametric experiment that is not estimable

Given $n$ independent and identically distributed observations and measuring the value of obtaining an additional observation in terms of Le Cam's notion of deficiency between experiments, we show for certain types of non-parametric experiments that the value of an additional observation decreases at a rate of $1/\sqrt{n}$. This is distinct from the known typical decrease at a rate of $1/n$ for parametric experiments and the non-decreasing value in the case of very large experiments. In particular, the rate of $1/\sqrt{n}$ holds for the experiment given by observing samples from a density about which we know only that it is bounded from below by some fixed constant. Thus there exists an experiment where the value of additional observations tends to zero but for which no estimator that is consistent (in total variation distance) exists.

math.ST↗

arXiv2020

Convex transform order of Beta distributions with some consequences

The convex transform order is one way to make precise comparison between the skewness of probability distributions on the real line. We establish a simple and complete characterisation of when one Beta distribution is smaller than another according to the convex transform order. As an application, we derive monotonicity properties for the probability of Beta distributed random variables exceeding the mean or mode of their distribution. Moreover, we obtain a simple alternative proof of the mode-median-mean inequality for unimodal distributions that are skewed in a sense made precise by the convex transform order. This new proof also gives an analogous inequality for the anti-mode of distributions that have a unique anti-mode. Such inequalities for Beta distributions follow as special cases. Finally, some consequences for the values of distribution functions of Binomial distributions near to their means are mentioned.

math.PR↗