如何在CPLEX中按单元格索引从Excel读取元组并支持动态范围？

Absolutely, you can make this work! The key is to dynamically construct the range string using CPLEX's string concatenation function, since your n value changes per scenario. Here's a step-by-step breakdown of how to implement this:

Step 1: Define or load your variable n #

First, ensure n is a known parameter (not a decision variable—SheetRead runs during data initialization, before solving). You can either hardcode it or read it directly from Excel:

int n;
// Example: Read n from Excel cell (1,0) (which is A2 in the "Data" sheet)
n from SheetRead(sheet, "'Data'!(1,0)");

Step 2: Build the dynamic range string #

Use the concat function to assemble your cell index range, inserting the variable n into the string:

string tupleRange = concat("'Data'!(0,0):(0,", n, ")");

This will generate a string like 'Data'!(0,0):(0,5) if n equals 5, exactly matching your desired format.

Step 3: Load your tuple using the dynamic range #

Pass the constructed string to SheetRead to pull in your tuple data:

// Define your tuple structure first
tuple MyTuple {
    int id;
    float value;
    // Add other elements as needed for your use case
}

// Declare your tuple array
MyTuple T[];

// Load data with the dynamically generated range
T from SheetRead(sheet, tupleRange);

Important Notes #

• CPLEX uses 0-based indexing for cell coordinates, so (0,0) directly corresponds to Excel's A1 cell—this aligns perfectly with your initial example.
• n must be a parameter (a fixed value known at data input time). Decision variables won't work here because SheetRead executes before the solve phase begins.
• Double-check that n is a non-negative integer and that your Excel sheet has enough data in the specified range. Out-of-bounds ranges will trigger CPLEX errors.

内容的提问来源于stack exchange，提问作者StabiloHB