Add specialized versions of change_coefficient (#15)

* Add specialized versions of change_coefficient

* add empty methods to mocksolver

Author: joaquimg

src/constraints/scalaraffine.jl

@@ -163,7 +163,7 @@ end
 MOI.canmodifyconstraint(m::LinQuadOptimizer, c::LCI{<: LinSets}, ::Type{MOI.ScalarCoefficientChange{Float64}}) = true
 function MOI.modifyconstraint!(m::LinQuadOptimizer, c::LCI{<: LinSets}, chg::MOI.ScalarCoefficientChange{Float64})
     col = m.variable_mapping[chg.variable]
-    change_coefficient!(m, m[c], col, chg.new_coefficient)
+    change_matrix_coefficient!(m, m[c], col, chg.new_coefficient)
 end
 
 #=
@@ -172,8 +172,7 @@ end
 
 MOI.canmodifyconstraint(m::LinQuadOptimizer, c::LCI{S}, ::Type{S}) where S <: Union{LE, GE, EQ} = true
 function MOI.modifyconstraint!(m::LinQuadOptimizer, c::LCI{S}, newset::S) where S <: Union{LE, GE, EQ}
-    # the column 0 (or -1 in 0-index) is the rhs.
-    change_coefficient!(m, m[c], 0, _getrhs(newset))
+    change_rhs_coefficient!(m, m[c], _getrhs(newset))
 end
 
 MOI.canmodifyconstraint(m::LinQuadOptimizer, c::LCI{IV}, ::Type{IV}) = true

src/constraints/vectoraffine.jl

@@ -53,7 +53,7 @@ MOI.canmodifyconstraint(m::LinQuadOptimizer, ::VLCI{<: VecLinSets}, ::Type{MOI.V
 function MOI.modifyconstraint!(m::LinQuadOptimizer, ref::VLCI{<: VecLinSets}, chg::MOI.VectorConstantChange{Float64})
     @assert length(chg.new_constant) == length(m[ref])
     for (r, v) in zip(m[ref], chg.new_constant)
-        change_coefficient!(m, r, 0, -v)
+        change_rhs_coefficient!(m, r, -v)
         m.constraint_constant[r] = v
     end
 end

src/mockoptimizer.jl

@@ -277,7 +277,7 @@ function LQOI.get_linear_constraint(instance::MockLinQuadOptimizer, idx)
 end
 
 # TODO SPLIT THIS ONE
-function LQOI.change_coefficient!(instance::MockLinQuadOptimizer, row, col, coef)
+function LQOI.change_matrix_coefficient!(instance::MockLinQuadOptimizer, row, col, coef)
     # if row == 0
     #     set_dblattrlist!(instance.inner, "Obj", Cint[col], Float64[coef])
     # elseif col == 0
@@ -287,7 +287,10 @@ function LQOI.change_coefficient!(instance::MockLinQuadOptimizer, row, col, coef
     #     #TODO fix this function in gurobi
     # end
 end
-
+function LQOI.change_rhs_coefficient!(instance::MockLinQuadOptimizer, row, coef)
+end
+function LQOI.change_objective_coefficient!(instance::MockLinQuadOptimizer, col, coef)
+end
 function LQOI.delete_linear_constraints!(instance::MockLinQuadOptimizer, rowbeg, rowend)
     if rowbeg > 1 && rowend < length(instance.inner.b)
         instance.inner.A = vcat(instance.inner.A[1:rowbeg-1,:],instance.inner.A[rowend+1:end,:])

src/objective.jl

@@ -124,5 +124,5 @@ function MOI.modifyobjective!(m::LinQuadOptimizer, chg::MOI.ScalarCoefficientCha
     end
     col = m.variable_mapping[chg.variable]
     # 0 row is the objective
-    change_coefficient!(m, 0, col, chg.new_coefficient)
+    change_objective_coefficient!(m, col, chg.new_coefficient)
 end

src/solver_interface.jl

@@ -180,7 +180,7 @@ function add_ranged_constraints! end
 
 Modify the lower and upperbounds of a ranged constraint in the model `m`.
 
-This is a special case compared to standard the `change_coefficient!` since it
+This is a special case compared to standard the `change_rhs_coefficient!` since it
 is often implemented via multiple API calls.
 """
 function modify_ranged_constraints! end
@@ -205,13 +205,27 @@ function get_linear_constraint end
 @deprecate lqs_getrows get_linear_constraint
 
 """
-    change_coefficient!(m, row, col, coef)
+    change_matrix_coefficient!(m, row, col, coef)
 
 Set the linear coefficient of the variable in column `col`, constraint `row` to
 `coef`.
 """
-function change_coefficient! end
-@deprecate lqs_chgcoef! change_coefficient!
+function change_matrix_coefficient! end
+@deprecate lqs_chgcoef! change_matrix_coefficient!
+
+"""
+change_objective_coefficient!(m, col, coef)
+
+Set the linear coefficient of the variable in column `col` to `coef` in the objective function.
+"""
+function change_objective_coefficient! end
+
+"""
+change_rhs_coefficient!(m, row, coef)
+
+Set the rhs of the constraint in row `row` to `coef`.
+"""
+function change_rhs_coefficient! end
 
 """
     delete_linear_constraints!(m, start_row::Int, end_row::Int)::Void