slp

SolHOP Linear Programming Solver.

Currently, the simplex method is implemented. Soon ILP and MIP will be supported.

This projetct is still in development. The APIs can change a lot before the first stable release v1.0.0.

Install and Run

Install

cargo install slp

Help

$ slp --help
slp 0.1.6
SolHOP Linear Programming Solver

USAGE:
    slp [FLAGS] <file>

FLAGS:
    -h, --help        Prints help information
    -p, --parallel    Enable data parallelism
    -r, --rat64       Use Rational64
    -V, --version     Prints version information

ARGS:
    <file>    Input file

Usage

slp input.txt

where input.txt contains the LP instance to be solved.

If no file is provided then input is taken from stdin.

To enable data parallelism use -p flag.

slp input.txt -p

Input format

The input is provided throught stdin.

An example of LP instance is

max        2x1 + 3x2
subject to 2x1 +  x2 <= 18
           6x1 + 5x2 <= 60
           2x1 + 5x2 <= 40
            x1       >= 0
            x2       >= 0

The corresponding input format is

3 2 # 3 is number of constraints and 2 is number of variables
2 3 # coefficients of objective function to be maximized: 2x1 + 3x2
2 1 18 # Constraint 1: 2x1 +  x2 <= 18
6 5 60 # Constraint 2: 6x1 + 5x2 <= 60
2 5 40 # Constraint 3: 2x1 + 5x2 <= 40
# x1 >= 0 and x2 >= 0 are always assumed

Output format

The output of the slp solver is sent to stdout and it can be one of the following:

INFEASIBLE

or

UNBOUNDED

or

OPTIMAL 28
SOLUTION 5 6

representing the objective value to be 28 and the solution as x1 = 5, x2 = 6.

Support for Rational LP Solver

To use Rational64 numbers, use -r flag.

Input:

3 2
-6 -3
-1 -1 -1
-2 1 -1
0 3 2

Output when run using command rsat input.txt:

OPTIMAL -5
SOLUTION 0.6666666666666666 0.33333333333333337

Output when run using command rsat -r input.txt:

OPTIMAL -5
SOLUTION 2/3 1/3

License

MIT