From 16959b35553e344111f5d05f1bb0341f92ac0354 Mon Sep 17 00:00:00 2001
From: phrb <pedro.bruel@gmail.com>
Date: Thu, 13 Aug 2015 20:29:14 -0300
Subject: [PATCH] Re-add optimize.jl.

---
 src/core/search/optimize.jl | 83 +++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 src/core/search/optimize.jl

diff --git a/src/core/search/optimize.jl b/src/core/search/optimize.jl
new file mode 100644
index 0000000..c9509d0
--- /dev/null
+++ b/src/core/search/optimize.jl
@@ -0,0 +1,83 @@
+initialize_cost(f::Function,
+                args::Dict{ASCIIString, Any},
+                evaluations::Int,
+                initial_x::Configuration) = begin
+    references = RemoteRef[]
+    costs      = Float64[]
+    for i = 1:evaluations
+        push!(references, @spawn f(initial_x, args))
+    end
+    for ref in references
+        push!(costs, fetch(ref))
+    end
+        mean(costs)
+end
+
+#
+# TODO Extract Methods.
+#
+optimize(f::Function,
+         initial_x::Configuration;
+         methods::Array{Symbol}       = [:simulated_annealing],
+         args::Dict{ASCIIString, Any} = Dict{ASCIIString,Any}(),
+         instances::Array{Int}        = [1],
+         iterations::Int              = 1_000,
+         report_after::Int            = 1_000,
+         evaluations::Int             = 3) = begin
+    #
+    # Alias no-arguments functions.
+    #
+    if isempty(args)
+        f_aliased(configuration, args) = f(configuration)
+    else
+        f_aliased = f
+    end
+    #
+    # Calculate Initial value for all Search Tasks.
+    #
+    initial_f_x = initialize_cost(f_aliased, args, evaluations, initial_x)
+    #
+    # Initialize Search Tasks
+    #
+    search_tasks = Task[]
+    for i = 1:length(methods)
+        if methods[i] == :simulated_annealing
+            for j = 1:instances[i]
+                push!(search_tasks, @task simulated_annealing(f_aliased,
+                                                              args,
+                                                              initial_x,
+                                                              initial_f_x,
+                                                              iterations  = iterations,
+                                                              evaluations = evaluations))
+            end
+        else
+            error("unknown method.")
+        end
+    end
+    #
+    # TODO Implement tests sharing between methods.
+    #      Implement result combination strategies.
+    #      Do it 'Round Robin' for now.
+    #
+    partial  = consume(search_tasks[rand(1:length(search_tasks))])
+    best     = deepcopy(partial)
+    produce(best)
+    iteration = 1
+    while(iteration <= iterations)
+        for task in search_tasks
+            partial = consume(task)
+            if partial.cost_minimum < best.cost_minimum
+                best = deepcopy(partial)
+            end
+        end
+        iteration += 1
+        best.current_iteration = iteration
+        if iteration == iterations
+            best.is_final = true
+            print(best)
+        elseif iteration % report_after == 0
+            print(best)
+        end
+        produce(best)
+    end
+end