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Need help to solve E-101: Incompatible types in assignment ('array of linctr' := 'linctr')
I am trying to solve a simple routing model using Xpress, but I obtain the error message as stated above. The error appears in every constraint where I have declared the constraint as
Contraint: array (indices) of linctr
One example of a constraint is:
forall (tt in TimePeriods) do
CargoCon :=
l(tt) = l(tt-1) + sum(ii in Locations) q(ii,tt);
end-do
declarations are:
CargoCon: array(TimePeriods) of linctr
l: dynamic array(TimePeriods) of mpvar
q: dynamic array (Locations, TimePeriods) of mpvar
Both TimePeriods and Locations are sets of integer values.
Thanks
2 Replies
You need to employ the index value (or index tuple) when enumerating the entries of an array of 'linctr', just like what you are doing for other types of arrays (eg array of mpvar) in your example:
forall (tt in TimePeriods)
CargoCon(tt) :=
l(tt) = l(tt-1) + sum(ii in Locations) q(ii,tt); ! NB: there probably needs to be a test on the 'tt-1' index, perhaps something like: if(t>1, l(tt-1), 0)
Worked like a charm! Yes, you were right. I had to implement "if (tt>=1) then " -statements on each constraint where this was the case.
Thank you.
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