From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: Emanuel Berg Newsgroups: comp.lang.ada Subject: how to analyze clock drift Date: Tue, 18 Nov 2014 23:12:04 +0100 Organization: Aioe.org NNTP Server Message-ID: <87bno4gnuz.fsf@debian.uxu> NNTP-Posting-Host: feB02bRejf23rfBm51Mt7Q.user.speranza.aioe.org Mime-Version: 1.0 Content-Type: text/plain X-Complaints-To: abuse@aioe.org User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux) X-Notice: Filtered by postfilter v. 0.8.2 Cancel-Lock: sha1:jEUtC8IGc+yzH1tF9Yq9DKIbVME= Mail-Copies-To: never Xref: news.eternal-september.org comp.lang.ada:23527 Date: 2014-11-18T23:12:04+01:00 List-Id: I have a long list of samples of clock readings. It "should" be periodical, by 1 ms, but of course it isn't. The data is in nanoseconds. Anyone knows how I can apply some math/stat method to find out the average drift, and/or if the drift will average out, or just about any conclusions you can get out of the material? Also, do you know of any rule-of-thumb how many readings I will need to make it "good science"? I will of course tell how many readings were used in the examination, but what would you say is a good benchmark were patterns will (almost foolproof) be visible? If you know of some tool that'd be great, or some formula, I'll just write a shell function, all such things are appreciated, or if you just want to share your knowledge. The file with the readings looks like this: 85033101286784 85033108461718 85033109544537 85033110621490 85033111714366 85033112794112 85033113871903 85033114934049 85033116009605 85033117089909 85033118169656 85033119256945 85033120336411 85033121409174 and so on. Hope to hear from you Ada real-time experts :) -- underground experts united