Update README

README.md

@@ -1,65 +1,101 @@
-# COIN-OR Linear Programming Interface (Clp.jl)
-
 ![](https://www.coin-or.org/wordpress/wp-content/uploads/2014/08/COINOR.png)
 
+# Clp.jl
+
 [![Build Status](https://github.com/jump-dev/Clp.jl/workflows/CI/badge.svg?branch=master)](https://github.com/jump-dev/Clp.jl/actions?query=workflow%3ACI)
 [![codecov](https://codecov.io/gh/jump-dev/Clp.jl/branch/master/graph/badge.svg)](https://codecov.io/gh/jump-dev/Clp.jl)
 
-`Clp.jl` is a wrapper for the [COIN-OR Linear Programming](https://projects.coin-or.org/Clp)
-solver.
+[Clp.jl](https://github.com/jump-dev/Clp.jl) is a wrapper for the
+[COIN-OR Linear Programming](https://projects.coin-or.org/Clp) solver.
 
 The wrapper has two components:
+
  * a thin wrapper around the complete C API
  * an interface to [MathOptInterface](https://github.com/jump-dev/MathOptInterface.jl)
 
-The C API can be accessed via `Clp.Clp_XXX` functions, where the names and
-arguments are identical to the C API.
+## Affiliation
+
+This wrapper is maintained by the JuMP community and is not a COIN-OR project.
 
-*Note: This wrapper is maintained by the JuMP community and is not a COIN-OR
-project.*
+## License
+
+`Clp.jl` is licensed under the [MIT License](https://github.com/jump-dev/Clp.jl/blob/master/LICENSE.md).
+
+The underlying solver, [coin-or/Clp](https://github.com/coin-or/Clp), is
+licensed under the [Eclipse public license](https://github.com/coin-or/Clp/blob/master/LICENSE).
 
 ## Installation
 
 Install Clp using `Pkg.add`:
-
 ```julia
-import Pkg; Pkg.add("Clp")
+import Pkg
+Pkg.add("Clp")
 ```
 
 In addition to installing the Clp.jl package, this will also download and
-install the Clp binaries. (You do not need to isntall Clp separately.)
+install the Clp binaries. You do not need to install Clp separately.
 
 To use a custom binary, read the [Custom solver binaries](https://jump.dev/JuMP.jl/stable/developers/custom_solver_binaries/)
 section of the JuMP documentation.
 
 ## Use with JuMP
 
-To use Clp with [JuMP](https://github.com/jump-dev/JuMP.jl), use `Clp.Optimizer`:
+To use Clp with JuMP, use `Clp.Optimizer`:
 ```julia
 using JuMP, Clp
-
 model = Model(Clp.Optimizer)
-set_optimizer_attribute(model, "LogLevel", 1)
-set_optimizer_attribute(model, "Algorithm", 4)
+set_attribute(model, "LogLevel", 1)
+set_attribute(model, "Algorithm", 4)
 ```
 
-See the list of options below.
+## MathOptInterface API
+
+The Clp optimizer supports the following constraints and attributes.
+
+List of supported objective functions:
+
+ * [`MOI.ObjectiveFunction{MOI.ScalarAffineFunction{Float64}}`](@ref)
+
+List of supported variable types:
+
+ * [`MOI.Reals`](@ref)
+
+List of supported constraint types:
+
+ * [`MOI.ScalarAffineFunction{Float64}`](@ref) in [`MOI.EqualTo{Float64}`](@ref)
+ * [`MOI.ScalarAffineFunction{Float64}`](@ref) in [`MOI.GreaterThan{Float64}`](@ref)
+ * [`MOI.ScalarAffineFunction{Float64}`](@ref) in [`MOI.Interval{Float64}`](@ref)
+ * [`MOI.ScalarAffineFunction{Float64}`](@ref) in [`MOI.LessThan{Float64}`](@ref)
+ * [`MOI.VariableIndex`](@ref) in [`MOI.EqualTo{Float64}`](@ref)
+ * [`MOI.VariableIndex`](@ref) in [`MOI.GreaterThan{Float64}`](@ref)
+ * [`MOI.VariableIndex`](@ref) in [`MOI.Interval{Float64}`](@ref)
+ * [`MOI.VariableIndex`](@ref) in [`MOI.LessThan{Float64}`](@ref)
+
+List of supported model attributes:
+
+ * [`MOI.ObjectiveSense()`](@ref)
 
 ## Options
 
-The following options are available to get/set via `JuMP.set_optimizer_attribute`
-or `MOI.RawOptimizerAttribute`.
+Options are, unfortunately, not well documented.
+
+The following options are likely to be the most useful:
 
-| Parameter | Default value | Description |
-|:----------|:--------------|:----------|
-| `PrimalTolerance` | `1e-7` | Primal feasibility tolerance |
-| `DualTolerance`   | `1e-7` | Dual feasibility tolerance |
+| Parameter            | Example | Explanation                                 |
+| -------------------- | ------- | ------------------------------------------- |
+| `PrimalTolerance`    | `1e-7`  | Primal feasibility tolerance                |
+| `DualTolerance`      | `1e-7`  | Dual feasibility tolerance                  |
 | `DualObjectiveLimit` | `1e308` | When using dual simplex (where the objective is monotonically changing), terminate when the objective exceeds this limit |
-| `MaximumIterations` | `2147483647` | Terminate after performing this number of simplex iterations |
-| `MaximumSeconds` | `-1.0` | Terminate after this many seconds have passed. A negative value means no time limit |
-| `LogLevel` | `1` | Set to 1, 2, 3, or 4 for increasing output. Set to `0` to disable output |
-| `PresolveType` | `0` | Set to 1 to disable presolve |
-| `SolveType` | `5` | Solution method: dual simplex (`0`), primal simplex (`1`), sprint (`2`), barrier with crossover (`3`), barrier without crossover (`4`), automatic (`5`) |
-| `InfeasibleReturn` | `0` | Set to 1 to return as soon as the problem is found to be infeasible (by default, an infeasibility proof is computed as well) |
-| `Scaling` | `3` | `0` -off, `1` equilibrium, `2` geometric, `3` auto, `4` dynamic(later) |
-| `Perturbation` | `100` | switch on perturbation (`50`), automatic (`100`), don't try perturbing (`102`) |
+| `MaximumIterations`  | `2147483647` | Terminate after performing this number of simplex iterations |
+| `MaximumSeconds`     | `-1.0`  | Terminate after this many seconds have passed. A negative value means no time limit |
+| `LogLevel`           | `1`     | Set to 1, 2, 3, or 4 for increasing output. Set to `0` to disable output |
+| `PresolveType`       | `0`     | Set to `1` to disable presolve              |
+| `SolveType`          | `5`     | Solution method: dual simplex (`0`), primal simplex (`1`), sprint (`2`), barrier with crossover (`3`), barrier without crossover (`4`), automatic (`5`) |
+| `InfeasibleReturn`   | `0`     | Set to 1 to return as soon as the problem is found to be infeasible (by default, an infeasibility proof is computed as well) |
+| `Scaling`            | `3`     | `0` -off, `1` equilibrium, `2` geometric, `3` auto, `4` dynamic(later) |
+| `Perturbation`       | `100`   | switch on perturbation (`50`), automatic (`100`), don't try perturbing (`102`) |
+
+## C API
+
+The C API can be accessed via `Clp.Clp_XXX` functions, where the names and
+arguments are identical to the C API.