Expressions Containing Set Mappings

These are mappings between sets, as defined in Mapping statements in TABLO Input file.

Values of set mappings are shown as real numbers (even though you possibly think of them as integers, or perhaps as strings). The relevant number indicates the position in the relevant set. Suppose for example that Com2Aggcom is a set mapping which maps the set COM to the set AGGCOM of aggregated commodities. If the value of "Com2Aggcom("c3") is 6.00, this means that "c3" from COM is mapped to the 6th element of AGGCOM.

In Formulas and Equations, set mappings only occur as part of the argument of a Coefficient or a Variable. So normally when you select (in the TABmate form) an expression which contains a set mapping you will be wanting to evaluate the Coefficient or Variable this set mapping occurs inside.

Occasionally you may wish to see the value of the expression just involving the set mapping.

An example will make this clear. [In this example, AGGCOM is a set of aggregated commodities. We suppose below that you are making selections in the TABmate form.]

Mapping Com2Aggcom from COM to AGGCOM ;

Formula (All,c,COM) Coef2(c) = aggc1(Com2Aggcom(c)) + 2 ;

Normally, if you click or select anywhere inside "aggc1(Com2Aggcom(c)), you would see the values of the whole expression since AnalyseGE extends the selection for you. However, in order to allow you to see the value of the set mapping expression "Com2Aggcom(c)" easily, we have made the following conventions:

•Suppose that you click (not select) anywhere inside a set mapping, that is, inside "Com2Aggcom" in the example. Then you will be asked if you want to see the values of the expression including the coefficient (that is, "aggc1"Com2Aggcom(c))" in the example), or those of the relevant expression involving the set mapping (namely, "Com2Aggcom(c)" in the example).

•Suppose that you select text starting anywhere inside a set mapping, that is, inside "Com2Aggcom" in the example, and suppose that you end the selection with the closing bracket for this set mapping. Then you will be shown the values of the relevant expression involving the set mapping (namely, "Com2Aggcom(c)" in the example).

These conventions apply in more complicated situations involving two or more set mappings inside an argument. To make this clear, consider the second example

aggc1(Com2Aggcom(Ind2Com(i)))

where Ind2Com is a set mapping from the set IND of industries to the set COM of commodities.

•If you click (not select) inside "Com2Aggcom" you will be asked if you wish to evaluate the coefficient expression (the whole expression above) or the relevant set mapping expression, namely "Com2Aggcom(Ind2Com(i))".

•If you click (not select) inside "Ind2Com" you will be asked if you wish to evaluate the coefficient expression (the whole expression above) or the relevant set mapping expression, namely "Ind2Com(i)".

•If you start your selection inside "Com2Aggcom" and end the selection with the corresponding closing bracket (the second one after "i") you will be shown the relevant set map expression, namely "Com2Aggcom(Ind2Com(i))".

•If you start your selection inside "Ind2Com" and end the selection with the corresponding closing bracket (the one after "i") you will be shown the relevant set map expression, namely "Ind2Com(i)".

URL of this topic: www.copsmodels.com/webhelp/analysege/hc_setmapexpression.htm

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