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# oximo
oximo is a Rust algebraic modeling library for mathematical optimization. It
provides a compact modeling API for variables, indexed domains, algebraic
constraints, objectives, nonlinear expressions, and multiple solver backends.
- [Webdocs](https://oximo.dev)
- [API documentation](https://docs.rs/oximo)
- [Examples](https://github.com/oximo-rs/oximo/tree/main/crates/oximo/examples)
- [Repository](https://github.com/oximo-rs/oximo)
```rust,ignore
use oximo::prelude::*;
use oximo::solvers::Highs;
let demand = [4.0, 6.0, 5.0];
let m = Model::new("production");
variable!(m, production[p in 0..2, t in 0..3] >= 0.0);
constraint!(m, meet[t in 0..3],
sum!(production[p, t] for p in 0..2) >= demand[t]);
objective!(m, Min, sum!(production[p, t] for p in 0..2, t in 0..3));
let mut solver = Highs;
let result = solver.solve(&m, &HighsOptions::default())?;
println!("objective = {:?}", result.objective());
# Ok::<(), Box<dyn std::error::Error>>(())
```
Expressions use standard Rust operators. Variable domains and bounds are
declared directly in the model:
```rust,ignore
variable!(m, x >= 0.0); // continuous
variable!(m, y, Bin); // binary
variable!(m, z >= 0.0, Int); // integer
constraint!(m, capacity, 2.0 * x + y <= 10.0);
objective!(m, Max, 3.0 * x + 4.0 * y);
```
Quadratic, nonlinear, and second-order-cone expressions are also available:
```rust,ignore
objective!(m, Min, (1.0 - x).powi(2) + 100.0 * (y - x.powi(2)).powi(2));
constraint!(m, disk, x.powi(2) + y.powi(2) <= 1.0);
soc_constraint!(m, cone, [x, y] <= t);
```
## Problem types
oximo supports the following algebraic problem classes. Which classes can be
solved depends on the selected backend:
- Linear programming (LP)
- Quadratic programming and quadratically constrained programming (QP/QCP)
- Nonlinear programming (NLP)
- Mixed-integer linear programming (MILP)
- Mixed-integer quadratic and quadratically constrained programming (MIQP/MIQCP)
- Mixed-integer nonlinear programming (MINLP)
- Second-order cone programming (SOCP/MISOCP)
## Solver features
| `highs` | HiGHS - LP/MILP/QP (bundled, requires a C/C++ compiler) | no |
| `io` | NL, MPS, and LP readers and writers | yes |
| `gurobi` | Gurobi v13+ (requires licensed install) | no |
| `mosek` | MOSEK 11.2 - convex LP/MIP/QP/QCP/SOCP | no |
| `gams` | GAMS bridge - capability depends on the selected sub-solver | no |
| `baron` | BARON - global non-convex solver (requires licensed install) | no |
| `clarabel` | Clarabel - LP/QP/SOCP (pure Rust, no install) | no |
| `clarabel-faer` | Clarabel with the faer sparse linear-algebra backend | no |
| `pounce` | POUNCE - pure-Rust LP/QP/QCP/NLP backend | no |
| `pounce-enzyme` | POUNCE with exact Enzyme derivatives (nightly) | no |
For example, use HiGHS for a bundled LP/MILP/QP solver:
```toml
[dependencies]
oximo = { version = "0.5", features = ["highs"] }
```
Licensed or external backends may require an installed solver, environment
variables, and a valid license. See the backend documentation and the
[webdocs](https://oximo.dev) for setup details.
## Results
`SolverResult` provides the termination status, objective value, variable values, duals, reduced costs, and (where supported) bounds, gaps, and solution pools.
## License
MIT OR Apache-2.0