Description
With this test we test a model instance with extra updater records and expect with a sufficiently large no_match_limit to succeed even if the entire updater has been squeezed out of the model. Contributor: Michael Bussieck, March 2021
Small Model of Type : GAMS
Category : GAMS Test library
Main file : embpy07.gms
$title Test no_match_limit for model instance (embpy07,SEQ=859)
$onText
With this test we test a model instance with extra updater records and expect
with a sufficiently large no_match_limit to succeed even if the entire updater
has been squeezed out of the model.
Contributor: Michael Bussieck, March 2021
$offText
$log --- Using Python library %sysEnv.GMSPYTHONLIB%
Set
i 'canning plants' / seattle, san-diego /
j 'markets' / new-york, chicago, topeka /;
Parameter
a(i) 'capacity of plant i in cases'
/ seattle 350
san-diego 600 /
b(j) 'demand at market j in cases'
/ new-york 325
chicago 300
topeka 275 /;
Table d(i,j) 'distance in thousands of miles'
new-york chicago topeka
seattle 2.5 1.7 1.8
san-diego 2.5 1.8 1.4;
Scalar f 'freight in dollars per case per thousand miles' / 90 /;
Parameter c(i,j) 'transport cost in thousands of dollars per case';
c(i,j) = f*d(i,j)/1000;
Parameter pen(*) / #j 999, doesNotExist 999 /, useShort /1/;
Variable
x(i,j) 'shipment quantities in cases'
short(j) 'supply slack'
z 'total transportation costs in thousands of dollars';
Positive Variable x;
Equation
cost 'define objective function'
supply(i) 'observe supply limit at plant i'
demand(j) 'satisfy demand at market j';
cost.. z =e= sum((i,j), c(i,j)*x(i,j)) + sum(j, short(j)*pen(j))$useShort;
supply(i).. sum(j, x(i,j)) =l= a(i);
demand(j).. sum(i, x(i,j)) =g= b(j) - short(j)$useShort;
Model transport / all /;
Set s 'scenarios to run' / base, run1, run2 /;
Table newsupply(s,i) 'updater for a (capacity)'
seattle san-diego
base 350 600
run1 300 650
run2 400 550;
Table newdemand(s,j) 'updater for b (demand)'
new-york chicago topeka
base 325 300 275
run1 325 300 275
run2 350 300 250;
$set solverlog
$if set useSolverLog $set solverlog output=sys.stdout
embeddedCode Python:
def solveMI(mi, symIn=[], symOut=[], nomatchlimit=0):
for sym in symIn:
gams.db[sym].copy_symbol(mi.sync_db[sym])
miopt = GamsModelInstanceOpt(no_match_limit = nomatchlimit)
mi.solve(mi_opt=miopt)
for sym in symOut:
try:
gams.db[sym].clear() # Explicitly clear the symbol to ensure setting "writtenTo" flag for sym
mi.sync_db[sym].copy_symbol(gams.db[sym])
except:
pass
pauseEmbeddedCode
abort$execerror 'Python error. Check the log';
$libInclude pyEmbMI tMI 'transport us lp min z' -all_model_types=cplex a.Zero b.Zero pen.Zero
useShort = 0;
$libInclude pyEmbMI tMInoShort 'transport us lp min z' -all_model_types=cplex a.Zero b.Zero pen.Zero
Parameter repX 'collector for level of x';
loop(s,
a(i) = newsupply(s,i);
b(j) = newdemand(s,j);
continueEmbeddedCode:
solveMI(tMI,['a','b','pen'],['x']) # will fail because of additional uel "doesnotexist" in pen
pauseEmbeddedCode x
);
abort$(execerror=0) 'expect execution errors';
execerror = 0;
loop(s,
a(i) = newsupply(s,i);
b(j) = newdemand(s,j);
continueEmbeddedCode:
solveMI(tMI,['a','b','pen'],['x'],999) # nomatchlimit because of additional uel "doesnotexist"
pauseEmbeddedCode x
repX('short',s,i,j) = x.l(i,j);
);
abort$(execerror<>0) 'expect no execution errors';
loop(s,
a(i) = newsupply(s,i);
b(j) = newdemand(s,j);
continueEmbeddedCode:
solveMI(tMInoShort,['a','b','pen'],['x']) # nomatchlimit because of squeezed out pen
pauseEmbeddedCode x
);
abort$(execerror=0) 'expect execution errors';
execerror = 0;
loop(s,
a(i) = newsupply(s,i);
b(j) = newdemand(s,j);
continueEmbeddedCode:
solveMI(tMInoShort,['a','b','pen'],['x'],999) # nomatchlimit because of squeezed out pen
pauseEmbeddedCode x
repX('noshort',s,i,j) = x.l(i,j);
);
abort$(execerror<>0) 'expect no execution errors';
option repX:0:2:2;
display repX;
Set error(s) 'empty solution';
error(s) = sum((i,j), repX('short',s,i,j)) = 0;
abort$card(error) 'Missing solution (short) for some scenarios', error;
error(s) = sum((i,j), repX('noshort',s,i,j)) = 0;
abort$card(error) 'Missing solution (noshort) for some scenarios', error;