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The TRANS Procedure

PROC TRANS Statement

PROC TRANS options ;

Input Data Set Options

CAPACITY=SAS-data-set
names the SAS data set that contains the capacity on each arc in the transportation network. These data specify the maximum allowable flow on each network arc. If the CAPACITY= option is omitted, then the value of the DEFCAPACITY= option is used for each arc in the network.

COST=SAS-data-set
names the SAS data set that contains the cost, supply, and demand data for the transportation network. If the COST= option is omitted, the most recently created SAS data set is used.

MINFLOW=SAS-data-set
names the SAS data set that contains the minimum flow data for the transportation network. These data specify the minimum required flow on each arc in the network. If the MINFLOW= option is omitted, then the value of the DEFMINFLOW= option is used for each arc in the network.

Output Data Set Options

OUT=SAS-data-set
specifies a name for the output data set. If the OUT= option is omitted, the SAS System creates a data set and names it according to the DATAn convention. Refer to the section "SAS Statements Used in the Data Set" in base SAS documentation for more information.

Other Options

DEFCAPACITY=c
specifies the default capacity for the arcs in the network. The default value of c is +\infty.

DEFMINFLOW=s
specifies the default minimum flow for the arcs in the network. The default value of s is 0.

DEMAND=d
gives the number of the observation that contains the number of units demanded at each destination node. The default value of d is 1.0. See the "Demand" section.

MAXIMUM
tells the procedure to maximize rather than minimize the objective function.

NOTHRUNET
tells PROC TRANS to drain away any excess supply (the amount that total supply exceeds total demand) or excess demand (the amount that total demand exceeds total supply). If total supply exceeds total demand and if a destination node demands d units of flow, then at least d units and maybe more will flow to that node. Similarly, if total demand exceeds total supply and if a source node supplies s units of flow, then at least s units and possibly more will flow from that node. If a transportation problem has unequal total supply and total demand, and you do not specify either the THRUNET or NOTHRUNET option, then PROC TRANS assumes that the problem is infeasible and does not proceed with the optimization. See the "Balancing Total Supply and Total Demand" section for more information.

THRUNET | ADDSUPPLY
tells the procedure to force through the network any excess supply (the amount that total supply exceeds total demand) or any excess demand (the amount that total demand exceeds total supply), as is required. If a transportation problem has unequal total supply and total demand, and you do not specify either THRUNET or NOTHRUNET, then PROC TRANS assumes that the problem is infeasible and does not proceed with the optimization. See the "Balancing Total Supply and Total Demand" section for more information.

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