This repository contains an **R** interface to the
**HiGHS** solver. The HiGHS solver, is a
**high**-performance open-source **solver**
for solving linear programming (LP), mixed-integer programming (MIP) and
quadratic programming (QP) optimization problems.

`::install_gitlab("roigrp/solver/roi.plugin.highs") remotes`

`library("ROI")`

```
# Minimize
# x_0 + x_1 + 3
# Subject to
# x_1 <= 7
# 5 <= x_0 + 2 x_1 <= 15
# 6 <= 3 x_0 + 2 x_1
# 0 <= x_0 <= 4
# 1 <= x_1
<- OP(
op objective = L_objective(c(1.0, 1)),
constraints = L_constraint(
L = rbind(c(0, 1), c(1, 2), c(1, 2), c(3, 2)),
dir = c("<=", ">=", "<=", ">="),
rhs = c(7, 5, 15, 6)
),bounds = V_bound(lb = c(0, 1), ub = c(4, Inf))
)
<- ROI_solve(op, "highs")
s solution(s)
#> [1] 0.50 2.25
```

```
# Minimize
# 2 x_0^2 + x_1^2 + x_0 x_1 + x_1 + x_2
# Subject to
# x_0 + x_1 = 1
# x_0, x_1 >= 0
<- OP(
op objective = Q_objective(rbind(c(2, .5), c(.5, 1)), c(1, 1)),
constraints = L_constraint(
L = rbind(c(1, 1)),
dir = "==",
rhs = 1
)
)
<- ROI_solve(op, "highs")
s solution(s)
#> [1] 0.25 0.75
```

For additional information on the **HiGHS** solver see
the HiGHS homepage, for additional
information on **ROI** see the ROI homepage.