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gams:mcp_pair_..._has_empty_equation_but_associated_variable_is_not_fixed

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gams:mcp_pair_..._has_empty_equation_but_associated_variable_is_not_fixed [2008/01/10 10:41]
Franz Nelissen created
gams:mcp_pair_..._has_empty_equation_but_associated_variable_is_not_fixed [2020/05/26 13:06]
Lutz Westermann model format
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 The message indicates that one of the equations is empty -- essentially,​ you have too many variables to be determined uniquely from the given equations. The message indicates that one of the equations is empty -- essentially,​ you have too many variables to be determined uniquely from the given equations.
  
-The model below will give (correctly) the same error : +The model below will give (correctly) the same error: 
- +<​code>​ 
-set i /i1,i2/; +Set i /i1,i2/; 
-alias (i,ii); +Alias (i,ii); 
-variables ​x(i); +Variables ​x(i); 
-equations ​e(i);+Equations ​e(i);
  
 e(i).. sum(ii$(ord(ii)=-1),​ x(ii)) =e= 0; e(i).. sum(ii$(ord(ii)=-1),​ x(ii)) =e= 0;
  
-model m /e.x/;+Model m /e.x/;
 solve m using mcp; solve m using mcp;
 +</​code>​
 The equation above is a  "​degenerate"​ case in the sense that the lhs vanishes. In that case the matching variable must be fixed (''​x.fx(i)=0;''​). ​ The equation above is a  "​degenerate"​ case in the sense that the lhs vanishes. In that case the matching variable must be fixed (''​x.fx(i)=0;''​). ​
  
 Most likely however you want to prevent such a situation from happening. Use an appropriate dollar condition on Most likely however you want to prevent such a situation from happening. Use an appropriate dollar condition on
 the equation such that this equation is not generated. the equation such that this equation is not generated.
- 
IMPRESSUM / LEGAL NOTICEPRIVACY POLICY gams/mcp_pair_..._has_empty_equation_but_associated_variable_is_not_fixed.txt · Last modified: 2020/05/26 13:06 by Lutz Westermann