# Transitioning from MathProgBase

MathOptInterface is a replacement for MathProgBase.jl. However, it is not a direct replacement.

## Transitioning a solver interface

MathOptInterface is more extensive than MathProgBase which may make its implementation seem daunting at first. There are however numerous utilities in MathOptInterface that the simplify implementation process.

For more information, read Implementing a solver interface.

## Transitioning the high-level functions

MathOptInterface doesn't provide replacements for the high-level interfaces in MathProgBase. We recommend you use JuMP as a modeling interface instead.

If you haven't used JuMP before, start with the tutorial Getting started with JuMP

`linprog`

Here is one way of transitioning from `linprog`

:

```
using JuMP
function linprog(c, A, sense, b, l, u, solver)
N = length(c)
model = Model(solver)
@variable(model, l[i] <= x[i=1:N] <= u[i])
@objective(model, Min, c' * x)
eq_rows, ge_rows, le_rows = sense .== '=', sense .== '>', sense .== '<'
@constraint(model, A[eq_rows, :] * x .== b[eq_rows])
@constraint(model, A[ge_rows, :] * x .>= b[ge_rows])
@constraint(model, A[le_rows, :] * x .<= b[le_rows])
optimize!(model)
return (
status = termination_status(model),
objval = objective_value(model),
sol = value.(x)
)
end
```

`mixintprog`

Here is one way of transitioning from `mixintprog`

:

```
using JuMP
function mixintprog(c, A, rowlb, rowub, vartypes, lb, ub, solver)
N = length(c)
model = Model(solver)
@variable(model, lb[i] <= x[i=1:N] <= ub[i])
for i in 1:N
if vartypes[i] == :Bin
set_binary(x[i])
elseif vartypes[i] == :Int
set_integer(x[i])
end
end
@objective(model, Min, c' * x)
@constraint(model, rowlb .<= A * x .<= rowub)
optimize!(model)
return (
status = termination_status(model),
objval = objective_value(model),
sol = value.(x)
)
end
```

`quadprog`

Here is one way of transitioning from `quadprog`

:

```
using JuMP
function quadprog(c, Q, A, rowlb, rowub, lb, ub, solver)
N = length(c)
model = Model(solver)
@variable(model, lb[i] <= x[i=1:N] <= ub[i])
@objective(model, Min, c' * x + 0.5 * x' * Q * x)
@constraint(model, rowlb .<= A * x .<= rowub)
optimize!(model)
return (
status = termination_status(model),
objval = objective_value(model),
sol = value.(x)
)
end
```