X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~yarrgweb/git?a=blobdiff_plain;f=yarrg%2Fweb%2Fdocs;h=e1269706dbba7e38a98cb84069140c6bf827293f;hb=422fab9f34f08090bca02f67cb41bba31f816c7e;hp=cbb1c0dd2a30dea8055aef2fae6d78c4b27d7954;hpb=97749b855cfaed019a2d70936c6c9eb2e261bb92;p=ypp-sc-tools.main.git diff --git a/yarrg/web/docs b/yarrg/web/docs index cbb1c0d..e126970 100755 --- a/yarrg/web/docs +++ b/yarrg/web/docs @@ -33,7 +33,7 @@ -Website documentation - YARRG +Website documentation - YARRG YARRG - @@ -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 +110,41 @@ 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 - 10 small 40 rum +
The capacity of a sloop which remains after + 10 small shot and 40 rum are loaded +
2t plus 500kg minus 200kg +
2300kg, with no limit on volume +
+Evaluation is strictly from left to right. -

Expected losses

+

+ +More formally: +

+ capacity-string := [ first-term term* ]
+ term := ('+' | '-' | 'plus' | 'minus') (value+ | number'%')
+ value := mass | volume
+        | integer commodity-name-or-abbreviation
+ mass := number ('t' | 'kg')
+ volume := number ('kl' | 'l')
+ first-term := mass | volume | mass volume | volume mass
+             | ship-name-or-abbreviation
+
+ +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 +162,15 @@ 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.

@@ -155,4 +184,22 @@ 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%; in each case it is taken as the loss for each league of the voyage. +

Available capital

+ +If you don't specify the amount of capital you have available to +invest in the voyage, the trading plan will assume that your capital +is unlimited. If you specify an amount in PoE here, the trading plan +will never require you to spend more than that amount on commodities. + +

+ +The trading plan does not take into account accumulated profits from +each leg of the journey when applying the available capital +constraint. For example, if you specify a journey from A to B to C +and a capital limit of 10000 PoE, the trading plan will not tell you +to buy 1000 peas at A for 10 PoE each, sail them to B and sell all of +them for 20 PoE each, and then buy 2000 beans at B for 10 PoE each and +sail them to C to sell for 20 PoE each even if such a trade would in +fact be possible. In practice this is unlikely to be a problem! + <& footer &>