You need --math instead of --glp. Best Regards,
Chris Matrakidis <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virus-free.www.avg.com <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Sun, 12 Nov 2023 at 21:08, Michael Hennebry <henne...@web.cs.ndsu.nodak.edu> wrote: > > From the glpk manual, I copied example E.1 to ex1.gmpl . > glpsol did not like it: > [hennebry@fedora triangle-free]$ glpsol --glp ex1.gmpl > GLPSOL--GLPK LP/MIP Solver 5.0 > Parameter(s) specified in the command line: > --glp ex1.gmpl > Reading problem data from 'ex1.gmpl'... > ex1.gmpl:1: error: problem line missing or invalid > GLPK LP/MIP file processing error > [hennebry@fedora triangle-free]$ > > Here is ex1.gmpl: > # A TRANSPORTATION PROBLEM > # > # This problem finds a least cost shipping schedule that meets > # requirements at markets and supplies at factories. > # > # References: > # > Dantzig G B, "Linear Programming and Extensions." > # > Princeton University Press, Princeton, New Jersey, 1963, > # > Chapter 3-3. > set I; > /* canning plants */ > set J; > /* markets */ > param a{i in I}; > /* capacity of plant i in cases */ > param b{j in J}; > /* demand at market j in cases */ > param d{i in I, j in J}; > /* distance in thousands of miles */ > > param f; > /* freight in dollars per case per thousand miles */ > param c{i in I, j in J} := f * d[i,j] / 1000; > /* transport cost in thousands of dollars per case */ > var x{i in I, j in J} >= 0; > /* shipment quantities in cases */ > minimize cost: sum{i in I, j in J} c[i,j] * x[i,j]; > /* total transportation costs in thousands of dollars */ > s.t. supply{i in I}: sum{j in J} x[i,j] <= a[i]; > /* observe supply limit at plant i */ > s.t. demand{j in J}: sum{i in I} x[i,j] >= b[j]; > /* satisfy demand at market j */ > data; > > set I := Seattle San-Diego; > set J := New-York Chicago Topeka; > param a := Seattle > San-Diego350 > 600; > param b := New-York > Chicago > Topeka325 > 300 > 275; > param d :New-York > 2.5 > 2.5 > Seattle > San-Diego > Chicago > 1.7 > 1.8 > param f := 90; > end; > > What is going on and what can I do about it? > > -- > Michael henne...@mail.cs.ndsu.nodak.edu > "I was just thinking about the life of a pumpkin. Grow up in the sun, > happily entwined with others, and then someone comes along, > cuts you open, and rips your guts out." -- Buffy >
