Hello. I am trying to export an AMPL model generated by a C++ script, but I am facing some issues with this. So, let’s consider the following C++ snippet.
#include "ampl/ampl.h"
using namespace ampl;
// init object
AMPL ampl;
// setup sets
...
// setup params
...
// setup vars
...
// setup objective function
...
// setup constraints
...
// setup options
ampl.setOption("solver", "ipopt");
ampl.setOption("ipopt_options", "mu_init=1e-2");
// export
ampl.exportData("data.dat", true);
ampl.exportData("model.mod");
The above code generates two files named as model.mod, and data.dat. When calling AMPL from the command line and inputting the two mentioned files, an error appears.
user@~/$ ampl
ampl: model model.mod;
ampl: data data.dat;
data.dat, line 11 (offset 244):
expected :=
context: : '0' '1' '10' >>> $ <<< 4 $5 $6 $7 $8 $9 '17' '2' '3' '4' '5' '6' '7' '8' '9' :=
In this context the generated data.dat file is a QAP instance. I suppose that the commands # $i = 'j' are renamings for reducings the length of the rows, but I still do not get why AMPL is not able to read such renamings. I would like to know if there is any way of avoiding these renamings, so I would be able to import such data file into AMPL command line, or if there is some AMPL flag for recognizing such renamings.
set N :=
'0' '2' '4' '6' '8' '10' '12' '14' '16'
'1' '3' '5' '7' '9' '11' '13' '15' '17';
param distance [*,*]
# $4 = '11'
# $5 = '12'
# $6 = '13'
# $7 = '14'
# $8 = '15'
# $9 = '16'
: '0' '1' '10' $4 $5 $6 $7 $8 $9 '17' '2' '3' '4' '5' '6' '7' '8' '9' :=
'0' 0 3 4 6 1 5 4 5 6 8 4 6 8 5 6 6 5 1
'1' 3 0 4 7 9 6 3 2 6 6 6 3 7 9 9 2 2 7
'10' 4 4 0 9 6 5 1 8 5 3 3 3 6 7 6 5 5 7
'11' 6 7 9 0 6 5 4 5 4 6 6 6 7 5 7 3 2 7
'12' 1 9 6 6 0 5 7 4 5 2 5 3 7 1 1 7 4 5
'13' 5 6 5 5 5 0 5 3 2 4 6 4 3 8 8 5 5 6
'14' 4 3 1 4 7 5 0 8 5 6 2 7 3 5 5 9 4 5
'15' 5 2 8 5 4 3 8 0 6 8 6 8 3 4 6 4 5 5
'16' 6 6 5 4 5 2 5 6 0 3 5 3 4 3 7 4 4 6
'17' 8 6 3 6 2 4 6 8 3 0 7 2 4 3 6 4 7 10
'2' 4 6 3 6 5 6 2 6 5 7 0 2 6 4 4 4 2 6
'3' 6 3 3 6 3 4 7 8 3 2 2 0 5 5 3 3 9 4
'4' 8 7 6 7 7 3 3 3 4 4 6 5 0 4 3 4 5 7
'5' 5 9 7 5 1 8 5 4 3 3 4 5 4 0 8 5 5 5
'6' 6 9 6 7 1 8 5 6 7 6 4 3 3 8 0 6 8 4
'7' 6 2 5 3 7 5 9 4 4 4 4 3 4 5 6 0 1 5
'8' 5 2 5 2 4 5 4 5 4 7 2 9 5 5 8 1 0 4
'9' 1 7 7 7 5 6 5 5 6 10 6 4 7 5 4 5 4 0
;
param flow [*,*]
# $4 = '11'
# $5 = '12'
# $7 = '14'
# $8 = '15'
# $9 = '16'
: '0' '1' '10' $4 $5 '13' $7 $8 $9 '17' '2' '3' '4' '5' '6' '7' '8' '9' :=
'0' 0 1 6 7 8 9 7 8 4 5 2 2 3 4 4 5 3 5
'1' 1 0 5 6 7 8 6 7 3 4 1 1 2 3 3 4 2 4
'10' 6 5 0 1 2 3 1 2 6 7 4 4 3 2 2 1 5 1
'11' 7 6 1 0 1 2 2 3 7 8 5 5 4 3 3 2 6 2
'12' 8 7 2 1 0 1 1 2 8 9 6 6 5 4 4 3 7 3
'13' 9 8 3 2 1 0 2 1 9 10 7 7 6 5 5 4 8 4
'14' 7 6 1 2 1 2 0 1 7 8 5 5 4 3 3 2 6 2
'15' 8 7 2 3 2 1 1 0 8 9 6 6 5 4 4 3 7 3
'16' 4 3 6 7 8 9 7 8 0 1 2 4 3 4 4 5 1 5
'17' 5 4 7 8 9 10 8 9 1 0 3 5 4 5 5 6 2 6
'2' 2 1 4 5 6 7 5 6 2 3 0 2 1 2 2 3 1 3
'3' 2 1 4 5 6 7 5 6 4 5 2 0 1 2 2 3 3 3
'4' 3 2 3 4 5 6 4 5 3 4 1 1 0 1 1 2 2 2
'5' 4 3 2 3 4 5 3 4 4 5 2 2 1 0 2 3 3 1
'6' 4 3 2 3 4 5 3 4 4 5 2 2 1 2 0 1 3 1
'7' 5 4 1 2 3 4 2 3 5 6 3 3 2 3 1 0 4 2
'8' 3 2 5 6 7 8 6 7 1 2 1 3 2 3 3 4 0 4
'9' 5 4 1 2 3 4 2 3 5 6 3 3 2 1 1 2 4 0
;
param warm_start [*,*]
: '0' '1' '10' '11' '12' '13' '14' '15' '16' '17' '2' '3' '4' '5' '6' :=
'0' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 1 -1 -1 -1 -1
'1' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
'10' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 1 -1 -1 -1
'11' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
'12' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
'13' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
'14' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
'15' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
'16' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
'17' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
'2' -1 -1 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
'3' -1 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
'4' -1 -1 -1 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
'5' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 1 -1 -1
'6' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 1 -1
'7' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 1
'8' -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
'9' 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
: '7' '8' '9' :=
'0' -1 -1 -1
'1' -1 -1 1
'10' -1 -1 -1
'11' -1 1 -1
'12' -1 -1 -1
'13' -1 -1 -1
'14' -1 -1 -1
'15' -1 -1 -1
'16' -1 -1 -1
'17' -1 -1 -1
'2' -1 -1 -1
'3' -1 -1 -1
'4' -1 -1 -1
'5' -1 -1 -1
'6' -1 -1 -1
'7' -1 -1 -1
'8' 1 -1 -1
'9' -1 -1 -1
;
Furthermore, I noticed that my AMPL options
// setup options
ampl.setOption("solver", "ipopt");
ampl.setOption("ipopt_options", "mu_init=1e-2");
weren’t exported to the model.mod. Is there any additional function/flag from the C++ API I have to call for this?
set N;
param distance{N, N};
param flow{N, N};
param warm_start{N, N};
var x{N, N} >=0
<= 1;
subject to from{i in N} : sum{k in N} x[i,k] == 1;
subject to to{k in N} : sum{i in N} x[i,k] == 1;
minimize cost: sum{i in N, j in N, k in N, l in N} x[i,k]*x[j,l]*distance[k,l]*flow[i,j];
Thanks and regards.