help: error executing solve command
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Tayup Leets
Dec 11, 2021, 2:39:33 PM12/11/21
to AMPL Modeling Language
Hello! I wonder if you could help me correct my mistake in the code shown below.
Upon trying to solve the model, ampl show me the following:
ampl: model Term3.mod;
ampl: data Term3.dat;
ampl: solve;
Error executing "solve" command:
error processing param cost:
2 invalid subscripts discarded:
cost[100,150,210]
cost[204,208,207]
Error executing "solve" command:
error processing objective Total_distance_cost:
invalid subscript cost[0,0,1]
ampl:
How could I possibly correct said error? Thank you very much for your help.
Upon trying to solve the model, ampl show me the following:
ampl: model Term3.mod;
ampl: data Term3.dat;
ampl: solve;
Error executing "solve" command:
error processing param cost:
2 invalid subscripts discarded:
cost[100,150,210]
cost[204,208,207]
Error executing "solve" command:
error processing objective Total_distance_cost:
invalid subscript cost[0,0,1]
ampl:
How could I possibly correct said error? Thank you very much for your help.
AMPL Google Group
Dec 12, 2021, 3:37:26 PM12/12/21
to AMPL Modeling Language
You defined the parameter cost and its data like this:
param cost {i in I, j in I, v in V};
.......
data;
param cost := 100 150 210 205 204 208 207 200 ;
This assigns the value 205 to cost[100,150,210], and the value 200 to cost[204,208,207]. That is clearly not what you wanted, and it is the cause of the first "invalid subscript" message. To see some ways of correctly giving data for a param indexed over 3 sets, see Chapter 9 of the AMPL book, particularly "Lists of higher-dimensional sets and parameters" on page 148, and "Two-dimensional slices of higher-dimensional data" on page 156.
The second "invalid subscript" message says that you refer to cost[0,0,1] in the objective function expression. So when you enter the correct data for parameter cost, you should be sure to include a value for cost[0,0.1].
param cost {i in I, j in I, v in V};
.......
data;
param cost := 100 150 210 205 204 208 207 200 ;
This assigns the value 205 to cost[100,150,210], and the value 200 to cost[204,208,207]. That is clearly not what you wanted, and it is the cause of the first "invalid subscript" message. To see some ways of correctly giving data for a param indexed over 3 sets, see Chapter 9 of the AMPL book, particularly "Lists of higher-dimensional sets and parameters" on page 148, and "Two-dimensional slices of higher-dimensional data" on page 156.
The second "invalid subscript" message says that you refer to cost[0,0,1] in the objective function expression. So when you enter the correct data for parameter cost, you should be sure to include a value for cost[0,0.1].
--
Robert Fourer
am...@googlegroups.com
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