This is an experimental and proof-of-concept package that allows JuMP to be combined with units using DynamicQuantities.
Currently, the package only supports a limited set of the JuMP functionality.
Note that this version allows different units to be combined in the same expression by converting all terms to SI base units.
Variables are defined with units using the @variable macro by adding the unit
as a separate argument:
@variable(m, speed, us"m/s")
@variable(m, length, us"cm")Note the use of the us to avoid eagerly transformation to SI base units.
Constraints are automatically created with units using the @constraint macro
if any of the involved parameters or variables have units. If one of the variables has units, all
variables must have units. This also includes binary variables that must be declared with an empty dimension.
period = 1.4u"s"
max_length = 1200u"m"
@constraint(m, period * speed + length <= max_length)Note that parameters in constraints must be declared with the normal u notation.
Both the @expression and @objective macros will handle variables with units
using DynQuantJuMP, HiGHS
m = Model(HiGHS.Optimizer)
@variable(m, x >= 0, us"m/s")
@variable(m, y >= 0, us"km/h")
max_speed = 60u"km/h"
@constraint(m, x + y <= max_speed)
@constraint(m, x <= 0.5y)
obj = @objective(m, Max, x + y)
optimize!(m)
println("x = $(value(x)) y = $(value(y))")
println("objective value = $(value(obj))")
#output x = 5.555555555555556 [m s⁻¹] y = 40.0 [km h⁻¹]
# objective value = 16.666666666666668 [m s⁻¹]