From b71ef311d22b2acc19b188d80a296c1d300df24c Mon Sep 17 00:00:00 2001
From: odow <o.dowson@gmail.com>
Date: Wed, 26 Apr 2023 17:02:32 +1200
Subject: [PATCH] Update

---
 src/core/objective.jl | 43 ++++++-------------------------------------
 1 file changed, 6 insertions(+), 37 deletions(-)

diff --git a/src/core/objective.jl b/src/core/objective.jl
index aca4167d..638ab604 100644
--- a/src/core/objective.jl
+++ b/src/core/objective.jl
@@ -123,37 +123,6 @@ function objective_min_fuel_and_flow_cost_polynomial(pm::AbstractPowerModel; kwa
     end
 end
 
-"""
-    _pow(x, i)
-
-A type-unstable version of `x^i` becaues using the base `x^i` for JuMP variables
-has some unusual behavior:
-
-```julia
-julia> model = Model();
-
-julia> @variable(model, x)
-x
-
-julia> typeof(x^1)
-QuadExpr (alias for GenericQuadExpr{Float64, VariableRef})
-
-julia> typeof(x^1.0)
-NonlinearExpr
-```
-"""
-function _pow(x, i)
-    if i == 0
-        return 1
-    elseif i == 1
-        return x
-    elseif i == 2
-        return x^2
-    else
-        return x^Float64(i)
-    end
-end
-
 
 ""
 function _objective_min_fuel_and_flow_cost_polynomial_linquad(pm::AbstractPowerModel; report::Bool=true)
@@ -165,7 +134,7 @@ function _objective_min_fuel_and_flow_cost_polynomial_linquad(pm::AbstractPowerM
             pg = sum( var(pm, n, :pg, i)[c] for c in conductor_ids(pm, n) )
             gen_cost[(n, i)] = JuMP.@expression(
                 pm.model,
-                sum(v * _pow(pg, d - 1) for (d, v) in enumerate(reverse(gen["cost"]))),
+                sum(v * pg^(d-1) for (d, v) in enumerate(reverse(gen["cost"]))),
             )
         end
 
@@ -174,7 +143,7 @@ function _objective_min_fuel_and_flow_cost_polynomial_linquad(pm::AbstractPowerM
             p_dc = sum( var(pm, n, :p_dc, from_idx[i])[c] for c in conductor_ids(pm, n) )
             dcline_cost[(n, i)] = JuMP.@expression(
                 pm.model,
-                sum(v * _pow(p_dc, d - 1) for (d, v) in enumerate(reverse(dcline["cost"]))),
+                sum(v * p_dc^(d-1) for (d, v) in enumerate(reverse(dcline["cost"]))),
             )
         end
     end
@@ -295,7 +264,7 @@ function _objective_min_fuel_and_flow_cost_polynomial_nl(pm::AbstractPowerModel;
             pg = sum( var(pm, n, :pg, i)[c] for c in conductor_ids(pm, n))
             gen_cost[(n,i)] = JuMP.@expression(
                 pm.model,
-                sum(v * _pow(pg, d-1) for (d, v) in enumerate(reverse(gen["cost"]))),
+                sum(v * pg^(d-1) for (d, v) in enumerate(reverse(gen["cost"]))),
             )
         end
 
@@ -305,7 +274,7 @@ function _objective_min_fuel_and_flow_cost_polynomial_nl(pm::AbstractPowerModel;
             p_dc = sum( var(pm, n, :p_dc, from_idx[i])[c] for c in conductor_ids(pm, n))
             dcline_cost[(n,i)] = JuMP.@expression(
                 pm.model,
-                sum(v * _pow(p_dc, d - 1) for (d, v) in enumerate(reverse(dcline["cost"]))),
+                sum(v * p_dc^(d-1) for (d, v) in enumerate(reverse(dcline["cost"]))),
             )
         end
     end
@@ -338,7 +307,7 @@ function _objective_min_fuel_cost_polynomial_linquad(pm::AbstractPowerModel; rep
             pg = sum( var(pm, n, :pg, i)[c] for c in conductor_ids(pm, n) )
             gen_cost[(n, i)] = JuMP.@expression(
                 pm.model,
-                sum(v * _pow(pg, d - 1) for (d, v) in enumerate(reverse(gen["cost"]))),
+                sum(v * pg^(d-1) for (d, v) in enumerate(reverse(gen["cost"]))),
             )
         end
     end
@@ -359,7 +328,7 @@ function _objective_min_fuel_cost_polynomial_nl(pm::AbstractPowerModel; report::
             pg = sum( var(pm, n, :pg, i)[c] for c in conductor_ids(pm, n))
             gen_cost[(n,i)] = JuMP.@expression(
                 pm.model,
-                sum(v * _pow(pg, d - 1) for (d, v) in enumerate(reverse(gen["cost"]))),
+                sum(v * pg^(d-1) for (d, v) in enumerate(reverse(gen["cost"]))),
             )
         end
     end