lpp-py

Linear problem parser and dual converter in Python.

YOU NEED numpy FOR THE PROGRAM TO WORK. INSTALL IT WITH pip install numpy

Usage

python3 lpp.py -i <inputFile> [options]

Example usage:

python3 lpp.py -i LP01.LTX

Options

    -i, --input  <inputFile>  : define input file name (mutually exclusive with -l)
    -l, --load   <inputFile>  : define input JSON file name to load
    -j, --json                : export problem in JSON format
    -o, --output <outputFile> : define output file name
                                (Default: '(LP-2)<inputFile>')
    -p, --print               : print the human readable output in the console
    -s, --simple              : export the simple human readable format
    -d, --dual                : convert the problem from primal to dual form

For help, use:

python3 lpp.py -h

python3 lpp.py --help

About input files:

You can either load an already saved json file, created with this program via -l or --load, but should be used instead of -i or --input.

Otherwise, the input file should follow some specific rules. Take a look below about what is true as well.

Start with the type of problem, min or max.
Follow up with the objective function, preferably on the same line.
Variable names must have specific names, like x1, x2, ..., xN. More specifically x and a number exactly after it.
Capitalization does NOT matter, in anything.
The order each variable is stated in an expression also does NOT matter.
After objective function you must use the keyword(s) s.t. or subject to and state each one per line.
Whitespace is irrelevant.
Optionally, you can use the keyword with and state the natural constraints per line. To do so, state the variable name, then type free or >=0 or <=0.
You must ALWAYS type the end keyword when you are done.
You can potentially write whatever else you like in the file and the parser will do it's utmost best to ignore them and only parse what it cares about. Take a look at the examples folder, there are some examples that cover most cases and answer additional questions you might have.

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