(!*********************************************************************
Mosel NL examples
=================
file airport_nl.mos
Locate N airports each within a specified distance of a
city centre, and minimise the sum of square of the distances
between all the airports.
QCQP problem.
Based on AMPL model airport.mod by Hande Y. Benson
Source: http://www.orfe.princeton.edu/~rvdb/ampl/nlmodels/cute/
Reference:
Rodrigo de Barros Nabholz & Maria Aparecida Diniz Ehrhardt
November 1994, DMA - IMECC- UNICAMP.
- XNLP version -
(c) 2008 Fair Issac Corporation
author: S. Heipcke, May 2008rev. Mar 2013
*********************************************************************!)
model "airport"
uses "mmxnlp"
declarations
RN: range ! Set of airports
R: array(RN) of real ! Square of max. distance to given location
CX,CY: array(RN) of real ! Target location for each point
x,y: array(RN) of mpvar ! x-/y-coordinates to determine
end-declarations
initialisations from "airport.dat"
CY CX R
end-initialisations
! Set bounds on variables
forall(i in RN) do
-10<=x(i); x(i)<=10
-10<=y(i); y(i)<=10
end-do
! Objective: minimise the total squared distance between all points
TotDist:= sum(i,j in RN | i<j) ((x(i)-x(j))^2+(y(i)-y(j))^2)
! Constraints: all points within given distance of their target location
forall(i in RN)
LimDist(i):= (x(i)-CX(i))^2+(y(i)-CY(i))^2 <= R(i)
setparam("XPRS_verbose", true);
minimise(TotDist);
writeln("Solution: ", getobjval);
forall(i in RN) writeln(i, ": ", getsol(x(i)), ", ", getsol(y(i)))
end-model
|
(!*********************************************************************
Mosel NL examples
=================
file airport_nl_graph.mos
`````````````````````````
Locate N airports each within a specified distance of a
city centre, and minimise the sum of square of the distances
between all the airports.
QCQP problem.
Based on AMPL model airport.mod by Hande Y. Benson
Source: http://www.orfe.princeton.edu/~rvdb/ampl/nlmodels/cute/
Reference:
Rodrigo de Barros Nabholz & Maria Aparecida Diniz Ehrhardt
November 1994, DMA - IMECC- UNICAMP.
- XNLP version, graph drawing -
(c) 2008 Fair Issac Corporation
author: S. Heipcke, May 2008, rev. Sep. 2017
*********************************************************************!)
model "airport"
uses "mmxnlp", "mmsvg"
declarations
RN: range ! Set of airports
R: array(RN) of real ! Square of max. distance to given location
CX,CY: array(RN) of real ! Target location for each point
x,y: array(RN) of mpvar ! x-/y-coordinates to determine
end-declarations
initialisations from "airport.dat"
CY CX R
end-initialisations
! Set bounds on variables
forall(i in RN) do
-10<=x(i); x(i)<=10
-10<=y(i); y(i)<=10
end-do
! Objective: minimise the total squared distance between all points
TotDist:= sum(i,j in RN | i<j) ((x(i)-x(j))^2+(y(i)-y(j))^2)
! Constraints: all points within given distance of their target location
forall(i in RN)
LimDist(i):= (x(i)-CX(i))^2+(y(i)-CY(i))^2 <= R(i)
setparam("XPRS_verbose", true);
minimise(TotDist);
writeln("Solution: ", getobjval);
forall(i in RN) writeln(i, ": ", getsol(x(i)), ", ", getsol(y(i)))
! **** Display the solution as user graph ****
! Scale the size of the displayed graph
svgsetgraphscale(50)
svgsetgraphpointsize(3)
svgsetgraphstyle(SVG_STROKEWIDTH,3)
! Draw the target locations
svgaddgroup("T", "Target area", SVG_SILVER)
svgsetstyle(SVG_FILL,SVG_CURRENT)
forall(i in RN) svgaddellipse(CX(i), CY(i), sqrt(R(i)), sqrt(R(i)))
! Draw the solution points
svgaddgroup("S", "Solution", SVG_BLUE)
forall(i in RN) svgaddpoint(x(i).sol, y(i).sol)
svgsave("airport.svg")
svgrefresh
svgwaitclose("Close browser window to terminate model execution.", 1)
end-model
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