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EMIS 8373: Integer Programming. Introduction to AMPL updated 10 January 2006. Starting AMPL. Entering the GT Railroad Problem. Solving the GT Railroad Problem. h. f. O. T. i. i. t. e. s. e. o. o. r. g. n. s. h. f. d. D. T. i. i. t. t. t. e. s.
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EMIS 8373: Integer Programming Introduction to AMPL updated 10 January 2006
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transport_model.txt set O; set D; param a {i in O}; param r {j in D}; param c {i in O, j in D}; var x {i in O, j in D} >= 0; minimize cost: sum {i in O, j in D} c[i,j] * x[i,j]; subject to supply {i in O}: sum {j in D} x[i,j] <= a[i]; subject to demand {j in D}: sum {i in O} x[i,j] >= r[j];
GT_data.txt set O := IE_Junction, Centerville, Wayover_City; set D := A_Station, Fine_Place, Goodville, Somewhere_Street; # supply param a := IE_Junction 4 Centerville 1 Wayover_City 2; # demand param r := A_Station 1 Fine_Place 1 Goodville 1 Somewhere_Street 1;
GT_data.txt param c : A_Station Fine_Place Goodville Somewhere_Street := IE_Junction 13 35 42 9 Centerville 6 61 18 30 Wayover_City 15 10 5 9 ;
Edited GT_data.txt set O := IE_Junction, Centerville, Wayover_City; set D := A_Station, Fine_Place, Goodville, Somewhere_Street; # supply param a := IE_Junction 3 Centerville 3 Wayover_City 3; # demand param r := A_Station 2 Fine_Place 2 Goodville 2 Somewhere_Street 2;
Using AMPL Student Edition on Windows • Download AMPL Student Edition • Download model and data file from Blackboard • transport_model.txt • GT_data.txt • Save the files in the amplcml directory created in step 1 • Double click on the AMPL icon to start AMPL
Viewing the Results • Quit AMPL • Open results.txt with WordPad or Word