{ "id": "1706.01478", "version": "v1", "published": "2017-06-05T18:09:36.000Z", "updated": "2017-06-05T18:09:36.000Z", "title": "An optimal $(ε,δ)$-approximation scheme for the mean of random variables with bounded relative variance", "authors": [ "Mark Huber" ], "comment": "12 pages, 1 figure", "categories": [ "stat.CO" ], "abstract": "Randomized approximation algorithms for many #P-complete problems (such as the partition function of a Gibbs distribution, the volume of a convex body, the permanent of a $\\{0,1\\}$-matrix, and many others) reduce to creating random variables $X_1,X_2,\\ldots$ with finite mean $\\mu$ and standard deviation$\\sigma$ such that $\\mu$ is the solution for the problem input, and the relative standard deviation $|\\sigma/\\mu| \\leq c$ for known $c$. Under these circumstances, it is known that the number of samples from the $\\{X_i\\}$ needed to form an $(\\epsilon,\\delta)$-approximation $\\hat \\mu$ that satisfies $\\mathbb{P}(|\\hat \\mu - \\mu| > \\epsilon \\mu) \\leq \\delta$ is at least $(2-o(1))\\epsilon^{-2} c^2\\ln(1/\\delta)$. We present here an easy to implement $(\\epsilon,\\delta)$-approximation $\\hat \\mu$ that uses $(2+o(1))c^2\\epsilon^{-2}\\ln(1/\\delta)$ samples. This achieves the same optimal running time as other estimators, but without the need for extra conditions such as bounds on third or fourth moments.", "revisions": [ { "version": "v1", "updated": "2017-06-05T18:09:36.000Z" } ], "analyses": { "subjects": [ "62K25", "65C05", "68W25" ], "keywords": [ "random variables", "bounded relative variance", "approximation scheme", "randomized approximation algorithms", "extra conditions" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable" } } }