X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~yarrgweb/git?a=blobdiff_plain;ds=sidebyside;f=yarrg%2Fweb%2Fdocs;h=6f754bff46e258472de8c5d413723ab7fa8eb117;hb=4c6a28f4cbed2ed351697f63f30fb4827259f6a9;hp=cbb1c0dd2a30dea8055aef2fae6d78c4b27d7954;hpb=5b88fe0fb309a1d55292c6b10b967481b78440d7;p=ypp-sc-tools.db-test.git diff --git a/yarrg/web/docs b/yarrg/web/docs index cbb1c0d..6f754bf 100755 --- a/yarrg/web/docs +++ b/yarrg/web/docs @@ -101,7 +101,7 @@ 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. -

Vessel capacity

+

Vessel capacity

If you don't specify a vessel or a vessel capacity, the trading plan will not take into account the fact that your voyage will be on a ship @@ -110,13 +110,36 @@ which trades excessively cumbersome goods (eg. hemp, wood, iron).

-So you should specify your vessel capacity. Currently you must -specify the actual mass and volume, as two numbers each with units. -The system understands the units t (tonnes), kg, l and kl -(kilolitres). There should be a space between the two limits, and no -space before the unit. +So you should specify your vessel capacity. You can enter things +like: +

+
sloop +
The capacity of a sloop, leaving no allowance for rum and shot +
wb - 1% +
The capacity of a war brig minus 1% +
13t 20kl +
13 tonnes (13,000kg), 20 kilolitres (20,000l) +
sloop - 100l 100kg +
The capacity of a sloop minus 100l, minus 100kg +
2t plus 500kg minus 200kg +
2300kg, with no limit on volume +
+Evaluation is strictly from left to right. -

Expected losses

+

+ +Formally, the capacity is a list of terms, all but the first preceded +by one of -, minus, +, +plus. Each term may specify a mass and/or a volume +(separated by a space), as a number followed (without an intervening +space) by a unit (t, kg, kl or +l). Alternatively each term except the first may specify a +percentage, which is applied as a percentage change to the answer from +all the preceding terms. The first term may be a ship name or +abbrevation instead. If the first term specifies only one of mass or +volume, all the subsequent terms may only adjust that same value. + +

Expected losses

In theory if you were guaranteed to have a trouble-free voyage it would be worth trading goods at very low margins. However, in @@ -134,14 +157,15 @@ to do.

-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. +Trades whose margin is less than the expected loss are never included +in the suggested plan. 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 it's not +possible to do both.