Difference: TransportationProblemInAMPL (5 vs. 6)

Revision 62008-04-02 - MichaelOSullivan

Line: 1 to 1

META TOPICPARENT	name="AMPLGuide"

The Transportation Problem in AMPL

Line: 53 to 53

>= Lower[i, j], <= Upper[i, j], integer;

Added:

>
>

Also, since some arcs no longer exist you should set a default of 0 for Cost (thus you don't have to define costs for non-existent arcs).

param Cost {SUPPLY_NODES, DEMAND_NODES} default 0;

Balancing Transportation Problems

Balanced transportation models are preferred as there is no confusion about the relational operators for the supply and demand constraints. We can use a script file (transportation.run) to balance any transportation problem automatically:

Line: 103 to 108

META FILEATTACHMENT	attachment="latexa518db3a714367f452620a2d18e0d61e.png" attr="h" comment="" date="1207132191" name="latexa518db3a714367f452620a2d18e0d61e.png" stream="GLOB(0xa4568f8)" tmpFilename="latexa518db3a714367f452620a2d18e0d61e.png" user="MichaelOSullivan" version="1"
META FILEATTACHMENT	attachment="latex57f16e685545faa46af73ecce6b4eb7c.png" attr="h" comment="" date="1207132191" name="latex57f16e685545faa46af73ecce6b4eb7c.png" stream="GLOB(0xa44d5e4)" tmpFilename="latex57f16e685545faa46af73ecce6b4eb7c.png" user="MichaelOSullivan" version="1"
META FILEATTACHMENT	attachment="latex15b62f2a4b15b2f0ea551529e221b54f.png" attr="h" comment="" date="1207132191" name="latex15b62f2a4b15b2f0ea551529e221b54f.png" stream="GLOB(0xa44d950)" tmpFilename="latex15b62f2a4b15b2f0ea551529e221b54f.png" user="MichaelOSullivan" version="1"

Changed:

<
<

META FILEATTACHMENT	attachment="transportation.mod" attr="" comment="" date="1207132918" name="transportation.mod" path="transportation.mod" size="1228" stream="transportation.mod" tmpFilename="" user="MichaelOSullivan" version="1"

>
>

META FILEATTACHMENT	attachment="transportation.mod" attr="" comment="" date="1207141133" name="transportation.mod" path="transportation.mod" size="1238" stream="transportation.mod" tmpFilename="" user="MichaelOSullivan" version="2"

META FILEATTACHMENT	attachment="transportation.run" attr="" comment="" date="1207132942" name="transportation.run" path="transportation.run" size="887" stream="transportation.run" tmpFilename="" user="MichaelOSullivan" version="1"

View topic | History: r9 < r8 < r7 < r6 | More topic actions...