Reading only selected columns from .tab file

Support
1

I have an ampl.tab format file containing data that I am using for multiple models. As a result, there are some columns that are only relevant to some of the models. Is there a way to read this data in without needing to define the irrelevant parameters?

For example, this is what the file looks like:

ampl.tab 1 8
CELL_IDS tableVal suppressionCost suppressionVal lowerBound upperBound LPL UPL
IA 20 20 0 0 190 0 0
IIC 22 22 1 0 190 5 5
TB 101 101 0 0 190 0 0

And in one model I might have the declarations

set CELL_IDS;
param tableVal {CELL_IDS};
param lowerBound {CELL_IDS};
param upperBound {CELL_IDS};

while the other has

set CELL_IDS;
param tableVal {CELL_IDS};
param suppressionVal {CELL_IDS};
param suppressionCost {CELL_IDS};
param LPL {CELL_IDS};
param UPL {CELL_IDS};
2

You can use a different table statement for each model, listing only the columns that you want to read. For example, to read data for the first model, you can define

table data1 IN "alldata.tab": 
   CELL_IDS <- [CELL_IDS], tableVal, lowerBound, upperBound;

Then read table data1 will read only the columns tableVal, lowerBound, and upperBound from alldata.tab. The columns not listed in the table statement will be ignored, and you will not need to define parameters corresponding to those columns.

3

Thank you so much! I thought I had tried that, but I must have gotten the syntax wrong the first time around. It works perfectly well now.