library(lpSolveAPI)
my.lp <- make.lp(nrow = 3, ncol = 2)
set.column(my.lp, 1, c(1, 1, 2))
set.column(my.lp, 2, c(3, 1, 0))
set.objfn(my.lp, c(1, 0))
set.constr.type(my.lp, rep("<=", 3))
set.rhs(my.lp, c(4, 2, 3))
set.bounds(my.lp, lower = c(-Inf, -Inf), upper = c(Inf, Inf))
> my.lp
Model name:
C1 C2
Minimize 1 0
R1 1 3 <= 4
R2 1 1 <= 2
R3 2 0 <= 3
Kind Std Std
Type Real Real
Upper Inf Inf
Lower -Inf -Inf
In my.lp, the objective function is set to minimization. How can I change this to maximization? It's not clear to me by looking at the help page of set.objfn.
Set the sense (minimize/maximize) with lp.control.
lp.control(my.lp, sense="max")
my.lp
#Model name:
# C1 C2
#Maximize 1 0
#R1 1 3 <= 4
#R2 1 1 <= 2
#R3 2 0 <= 3
#Kind Std Std
#Type Real Real
#Upper Inf Inf
#Lower -Inf -Inf
solve(my.lp) # returns 0, success
#[1] 0
get.variables(my.lp)
#[1] 1.5 0.0
get.objective(my.lp)
#[1] 1.5