The following sample currency rate table is defined with several rate entries (the rates are fictitious):
From | To | Rate |
---|---|---|
EUR | BEF | 2.217436 |
EUR | FIM | 4.323233 |
EUR | FRF | 7.261892 |
GBP | USD | 1.563321 |
USD | CHF | 0.813 |
CHF | USD | 1.252 |
Note that this table provides conversion rates between the euro dollar and three national currencies. When specifying a conversion rate involving the euro dollar, it is only permissible to specify the rate in terms of the quantity of currency for a nation equals a single euro dollar. This rate is then used as a multiplier or divisor (as appropriate) to perform all calculations.
As the two entries between USD (US Dollars) and CHF (Swiss Francs) demonstrates, individual rates may be specified when dealing directly with currencies other than the euro dollar. If a rate is provided for converting in a single direction only, the rate will be used as a multiplier or divisor (as appropriate) to perform all calculations.
Triangulation is used as a method for converting currencies via the euro dollar only. The table above permits conversion from Belgian Francs (BEF) to French Francs via triangulation with the euro dollar. Conversely, conversion from British Pounds (GBP) to Swiss Francs (CHF) via triangulation with the US Dollar (USD) is not supported.