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Telecommunication problems Description
Further explanation of this example: 'Applications of optimization with Xpress-MP', Chapter 12: Telecommunication problems
Source Files
Data Files
g4cable.mos (!****************************************************** Mosel Example Problems ====================== file g4cable.mos ```````````````` Connecting terminals through cables (c) 2008 Fair Isaac Corporation author: S. Heipcke, Apr. 2002 *******************************************************!) model "G-4 Cabled network" uses "mmxprs" declarations NTERM = 6 TERMINALS = 1..NTERM ! Set of terminals to connect DIST: array(TERMINALS,TERMINALS) of integer ! Distance between terminals connect: array(TERMINALS,TERMINALS) of mpvar ! 1 if direct connection ! between terminals, 0 otherwise level: array(TERMINALS) of mpvar ! level value of nodes end-declarations initializations from 'g4cable.dat' DIST end-initializations ! Objective: length of cable used Length:= sum(s,t in TERMINALS | s<>t) DIST(s,t)*connect(s,t) ! Number of connections sum(s,t in TERMINALS | s<>t) connect(s,t) = NTERM - 1 ! Avoid subcycle forall(s,t in TERMINALS | s<>t) level(t) >= level(s) + 1 - NTERM + NTERM*connect(s,t) ! Direct all connections towards the root (node 1) forall(s in 2..NTERM) sum(t in TERMINALS | s<>t) connect(s,t) = 1 forall(s,t in TERMINALS | s<>t) connect(s,t) is_binary ! Solve the problem minimize(Length) ! Solution printing writeln("Cable length: ", getobjval) write("Connections:") forall(s,t in TERMINALS | s<>t) write(if(getsol(connect(s,t))>0, " " + s + "-" + t, "")) writeln end-model | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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