Hi,
I have a MIP model and am running into an issue when inputting data from csv
files versus entering them into the data section of the model file. The issue
involves symbolic parameters that are referenced in multiple data sets. For
example, I have two sets:
{n in Nodes} and {b in Blocks}. The Blocks set has a parameter Block_Node that
matches one of the Nodes. The data reads just fine from the csv files, as when
I use the display statement I get the following:
Display statement at line 153
Block_Node[1] = 1
Display statement at line 154
Nodes:
1
719
742
752
787
791
793
796
823
828
I create a set of BlockNodes using the following:
set BlockNodes:=setof{b in Blocks, n in Nodes: (Node_ID[n]=Block_Node[b])}
(b,n);
However, when the data is input from csv files, glpk does not recognize this
join. When I try to display the set BlockNodes, I get the following error:
"no value for Node_ID[1]"
If rather than using csv files, I enter the same data at the end of the model
file, the model solves with no issue.
I am thinking that using the csv files is causing a data type conversion issue.
I have tried forcing the Node_IDs and Block_Nodes to text by using quotation
marks but the issue persisted.
Any help would be much appreciated. Thanks,
Joel
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