CppLEX

2021 · university-coursework

CppLEX: a Primal Simplex Algorithm implementation.

This is a C++ implementation of the Primal Simplex Algorithm, done within the scope of the course Programació Matemàtica from the Bachelor’s Degree in Mathematics at UPC-BarcelonaTech.

Installation

To install this repository, you can run the following command

git clone git@github.com:Atellas23/CppLEX
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Once you have cloned the repository, you can cd CppLEX into the directory, and execute make to compile the code. After this steps, you are all set to use the program. If you want to, you can test the functions used in the code by issuing make test (NOTE: the results are only in spanish).

Usage

Once you have the repository installed and the code compiled, you can use the program to find solutions to a Linear Programming problem in standard form, which is

(PL)    min z = c'x
        s.t.:
                Ax = b
                x >= 0
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The problem data shall be submitted to the program in the following format: a plaintext file (the extension is not important, as long as it’s a plaintext file) with the matrix A, followed by the line end of matrix, followed by a line with the restrictions b, followed by the line end of restrictions, followed by a line with the cost vector c, followed by the line end of costs. For example, the following (which is the content of the data_model file) would be an acceptable format for the input of our implementation:

1 0 0 0
0 1 0 0
0 0 1 0
0 0 0 1
end of matrix
0 0 0 0
end of restrictions
1 1 1 1
end of costs
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Then, suppose this is stored in a file named data.txt. Then, you can simply execute ./simplex.exe data.txt and you are good to go. When the algorithm finishes, you will have a report of the results both in the terminal and in a file named like the input data file with the extension .out.

Credits

Àlex Batlle & Jose Pérez, 2020.