Hi everyone,
I’m using Python to call GAMS to solve an MIP problem. There are 6 parameters that need to be updated. When the model was run, the following problem occurred.
When the parameters “COST” and “WD” were commented out, the model run successfully.
What should I do about this problem?
Here are the model and input files.
Thanks~
model and input.rar (9.97 KB)
The error message “Unmatched record limit exceeded while processing modifier COST, for more info check GamsModelInstanceOpt parameter no_match_limit” is a good start to debug. The default no_match_limit is 0, so all records in the syncDB need a parameter in the model. For COST syncDB contains:
Parameter COST(*) Cost /
'1' 9900,
'2' 39900,
'3' 0.38,
'4' 1.48,
'5' 0.15,
'6' 0.236,
'7' 0.15,
'8' 0.314,
'9' 0.154 /;
while the model misses COST(‘2’). You can e.g. use the “solver” convert with option “dict” to see the elements of the model. Please note that the modifiable parameters are turned into variables and get an additional suffix “_var”, so for COST we have:
x513 COST_var(1)
x514 COST_var(3)
x515 COST_var(4)
x516 COST_var(5)
x517 COST_var(6)
x518 COST_var(7)
x519 COST_var(8)
x520 COST_var(9)
With symbol WD it is even worse. The syncDB has
Parameter WD(*,*) Water demand /
'1'.'1' 135.2074323,
'1'.'2' 126.6750235,
'1'.'3' 147.4151586,
'1'.'4' 151.8117234,
'1'.'5' 153.9757086,
'1'.'6' 123.7169225,
'1'.'7' 135.3514663,
'1'.'8' 117.5905595,
'1'.'9' 123.1176089,
'1'.'10' 113.2271104,
'1'.'11' 127.2642251,
'1'.'12' 126.3364306,
'2'.'1' 270.4148646,
'2'.'2' 253.3500469,
...
'8'.'12' 119.6750741,
'9'.'1' 746.2178706,
'9'.'2' 643.8894274,
'9'.'3' 741.9646101,
'9'.'4' 717.8106774,
'9'.'5' 671.2645794,
'9'.'6' 650.1859209,
'9'.'7' 695.4393613,
'9'.'8' 698.5354848,
'9'.'9' 684.96258,
'9'.'10' 715.965513,
'9'.'11' 730.1326232,
'9'.'12' 801.0307224 /;
while the model has
x569 WD_var(CXD,1)
x570 WD_var(CXD,2)
x571 WD_var(CXD,3)
x572 WD_var(CXD,4)
x573 WD_var(CXD,5)
x574 WD_var(CXD,6)
x575 WD_var(CXD,7)
x576 WD_var(CXD,8)
x577 WD_var(CXD,9)
x578 WD_var(CXD,10)
x579 WD_var(CXD,11)
x580 WD_var(CXD,12)
x581 WD_var(HLSH,1)
x582 WD_var(HLSH,2)
x583 WD_var(HLSH,3)
x584 WD_var(HLSH,4)
x585 WD_var(HLSH,5)
x586 WD_var(HLSH,6)
x587 WD_var(HLSH,7)
x588 WD_var(HLSH,8)
x589 WD_var(HLSH,9)
x590 WD_var(HLSH,10)
x591 WD_var(HLSH,11)
x592 WD_var(HLSH,12)
x593 WD_var(WFD,1)
x594 WD_var(WFD,2)
...
x664 WD_var(ZH,12)
x665 WD_var(KFQ,1)
x666 WD_var(KFQ,2)
x667 WD_var(KFQ,3)
x668 WD_var(KFQ,4)
x669 WD_var(KFQ,5)
x670 WD_var(KFQ,6)
x671 WD_var(KFQ,7)
x672 WD_var(KFQ,8)
x673 WD_var(KFQ,9)
x674 WD_var(KFQ,10)
x675 WD_var(KFQ,11)
x676 WD_var(KFQ,12)
The COST issue you could resolve by increasing no_match_limit, but the WD issue needs to be dealt with properly. Either use 1 to 9 inside GAMS or fill the syncDB with proper customer names.
You need to understand how to debug such issues and I hope I have given you some pointers how to accomplish this.
-Michael