Merge pull request kodecocodes#733 from dynamite8/jc_fixes_issue731

Fixes Issue#371: Simulated Annealing demo crashes

Author: kelvinlauKL

Simulated annealing/simann.swift

@@ -22,16 +22,6 @@
  import Glibc
 #endif
 
-public extension Double { 
- public static func random(_ lower: Double, _ upper: Double) -> Double {
- #if os(OSX)
- return (Double(arc4random()) / 0xFFFFFFFF) * (upper - lower) + lower
- #elseif os(Linux)
- return (Double(random()) / 0xFFFFFFFF) * (upper - lower) + lower
- #endif
- }
-}
-
 protocol Clonable {
  init(current: Self)
 }
@@ -85,13 +75,13 @@ func SimulatedAnnealing<T: SAObject>(initial: T, temperature: Double, coolingRat
 
  while temp > 1 { 
  let newSolution: T = currentSolution.clone()
- let pos1: Int = Int(arc4random_uniform(UInt32(newSolution.count)))
- let pos2: Int = Int(arc4random_uniform(UInt32(newSolution.count)))
+ let pos1: Int = Int.random(in: 0 ..< newSolution.count)
+ let pos2: Int = Int.random(in: 0 ..< newSolution.count)
  newSolution.randSwap(a: pos1, b: pos2)
  let currentEnergy: Double = currentSolution.currentEnergy()
  let newEnergy: Double = newSolution.currentEnergy()
 
- if acceptance(currentEnergy, newEnergy, temp) > Double.random(0, 1) {
+ if acceptance(currentEnergy, newEnergy, temp) > Double.random(in: 0 ..< 1) {
  currentSolution = newSolution.clone()
  }
  if currentSolution.currentEnergy() < bestSolution.currentEnergy() {

Simulated annealing/simann_example.swift

@@ -18,21 +18,11 @@
 
 #if os(OSX)
  import Foundation
+ import Cocoa
 #elseif os(Linux)
  import Glibc
 #endif
 
-public extension Double {
- 
- public static func random(_ lower: Double, _ upper: Double) -> Double {
- #if os(OSX)
- return (Double(arc4random()) / 0xFFFFFFFF) * (upper - lower) + lower
- #elseif os(Linux)
- return (Double(random()) / 0xFFFFFFFF) * (upper - lower) + lower
- #endif
- }
-}
-
 protocol Clonable {
  init(current: Self)
 }
@@ -96,8 +86,8 @@ extension Point {
  static func <-> (left: Point, right: Point) -> Double {
  let xDistance = (left.x - right.x)
  let yDistance = (left.y - right.y)
- 
- return Double(sqrt(Double((xDistance * xDistance) + (yDistance * yDistance))))
+
+ return Double((xDistance * xDistance) + (yDistance * yDistance)).squareRoot()
  }
 }
 
@@ -128,15 +118,6 @@ extension Tour {
  self[a] = cpos2
  self[b] = cpos1
  }
- 
- func shuffle() {
- for i in stride(from: self.count - 1, through: 1, by: -1) {
- let j = Int(arc4random()) % (i + 1)
- if i != j {
- swap(&self.tour[i], &self.tour[j])
- }
- }
- }
 
  func currentEnergy() -> Double {
  if self.energy == 0 {
@@ -155,7 +136,10 @@ extension Tour {
  }
  return self.energy
  }
- 
+
+ func shuffle() {
+ self.shuffle()
+ }
 }
 
 // MARK: - subscript to manipulate elements of Tour.
@@ -180,13 +164,13 @@ func SimulatedAnnealing<T: SAObject>(initial: T, temperature: Double, coolingRat
 
  while temp > 1 {
  let newSolution: T = currentSolution.clone()
- let pos1: Int = Int(arc4random_uniform(UInt32(newSolution.count)))
- let pos2: Int = Int(arc4random_uniform(UInt32(newSolution.count)))
+ let pos1: Int = Int.random(in: 0 ..< newSolution.count)
+ let pos2: Int = Int.random(in: 0 ..< newSolution.count)
  newSolution.randSwap(a: pos1, b: pos2)
  let currentEnergy: Double = currentSolution.currentEnergy()
  let newEnergy: Double = newSolution.currentEnergy()
 
- if acceptance(currentEnergy, newEnergy, temp) > Double.random(0, 1) {
+ if acceptance(currentEnergy, newEnergy, temp) > Double.random(in: 0 ..< 1) {
  currentSolution = newSolution.clone()
  }
  if currentSolution.currentEnergy() < bestSolution.currentEnergy() {