# minilp
[](https://crates.io/crates/minilp)
[](https://docs.rs/minilp/)
A fast linear programming solver library.
[Linear programming](https://en.wikipedia.org/wiki/Linear_programming) is a technique for
finding the minimum (or maximum) of a linear function of a set of continuous variables
subject to linear equality and inequality constraints.
## Features
* Pure Rust implementation.
* Able to solve problems with hundreds of thousands of variables and constraints.
* Incremental: add constraints to an existing solution without solving it from scratch.
* Problems can be defined via an API or parsed from an
[MPS](https://en.wikipedia.org/wiki/MPS_(format)) file.
Warning: this is an early-stage project. Although the library is already quite powerful and fast,
it will probably cycle, lose precision or panic on some harder problems. Please report
bugs and contribute code!
## Examples
Basic usage
```rust
use minilp::{Problem, OptimizationDirection, ComparisonOp};
// Maximize an objective function x + 2 * y of two variables x >= 0 and 0 <= y <= 3
let mut problem = Problem::new(OptimizationDirection::Maximize);
let x = problem.add_var(1.0, (0.0, f64::INFINITY));
let y = problem.add_var(2.0, (0.0, 3.0));
// subject to constraints: x + y <= 4 and 2 * x + y >= 2.
problem.add_constraint(&[(x, 1.0), (y, 1.0)], ComparisonOp::Le, 4.0);
problem.add_constraint(&[(x, 2.0), (y, 1.0)], ComparisonOp::Ge, 2.0);
// Optimal value is 7, achieved at x = 1 and y = 3.
let solution = problem.solve().unwrap();
assert_eq!(solution.objective(), 7.0);
assert_eq!(solution[x], 1.0);
assert_eq!(solution[y], 3.0);
```
For a more involved example, see [examples/tsp](examples#tsp), a solver for the travelling
salesman problem.
## License
This project is licensed under the [Apache License, Version 2.0](./LICENSE).