-The system has two main parts: this website which maintains a -searchable database of commodity prices, and an upload client, which -screenscrapes the commodity data from the Puzzle Pirates game client -and uploads it to the database. +The Market prices database is the main output +from YARRG. It offers a variety of enquiry options. -
-The lookup page gives access to the uploaded data. +This website documentation page contains information about the +database website which you may not be able to divine from the online +user interface. -
-The current official version of YARRG for use as an upload -client can browsed here: - http://www.chiark.greenend.org.uk/~ijackson/ypp-sc-tools/master/ -See particularly the -YARRG README. +(An exception to this is if you select the `Update' option from the +`Trades for route' lookup; the list of (de)selected stalls is too long +to fit in a URL.) + +
-To install the client, install the `git' version control system -and the other dependencies listed in the `Installation requirements' -section of the README and then run: -
-git-clone http://www.chiark.greenend.org.uk/~ijackson/ypp-sc-tools/master/.git ypp-sc-tools -cd ypp-sc-tools -cd yarrg -make --this will download the code into the directory
ypp-sc-tools,
-and build the software.
+
+If you specify only one island or one archipelago, the site shows only
+arbitrage trades. If you want single-hop trades within an
+archipelago, you must enter the archipelago name twice.
-When new versions of the upload client are released, you can: -
-cd .../ypp-sc-tools -git-pull -cd yarrg -make --to fetch the new version. +After getting the results, you can untick various trades individually, +and select `Update' to get a new plan. The unticked trades will be +excluded from the voyage plan (if any) and also from the totals. -
-
-Not only the client but also the webserver code is Free. The website
-code can be found in the same tree as above, in the web
-directory.
+We model this by pretending that you expect to lose a fixed proportion
+of your stock each league you sail. This expected loss does not
+appear in the trade tables (although the distance does), but it does
+affect the way the voyage trading plan optimiser chooses which trades
+to do.
-But in case we have made changes but not yet pushed them -(perhaps because we haven't done a release), and to make it easy for -anyone else who runs a copy of the website to provide everyone with -the source for their version, the website code itself lets you download -an up-to-date tarball of its -actually-running source code. +Trades whose margin is less than the expected loss are never selected. +For example, if you select 1% loss per league, and plan a voyage of 5 +leagues, then any trade with a margin of less than 5.15% would be +completely excluded (5.15% not 5% because the loss works like compound +interest). Theoretically very profitable trades which are close to +the expected break-even point because of the distance can also be +rejected by the optimiser in favour of shorter distance trades with +theoretically smaller margins.
-If you would like to run a (perhaps modified) copy of the YARRG -website it would be very easy for us to make our system send you -copies of updates submitted by users of the official YARRG client, in -the format expected by the code you'll be running. Please just ask -us. +As a guide: you may expect to lose between 0.1% and 1% per league. +0.1% would correspond, for example, to losing one fight to brigands +every ten 10-league voyages. -
-Email Ian Jackson ijackson (at) chiark.greenend.org.uk. Or talk to -any Fleet Officer or above of the crew Special Circumstances on the -Midnight Ocean. +You can enter the value in the box either as a percentage, or as a +fraction 1/divisor, eg 1/200 is the same as 0.5%. -<& footer, isdocs => 1 &> +<& footer &>