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Commit 41c8d05

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cleaned up iris example
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  • Classic Computer Science Problems in Swift.playground/Pages/Chapter 7.xcplaygroundpage

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+24
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‎Classic Computer Science Problems in Swift.playground/Pages/Chapter 7.xcplaygroundpage/Contents.swift

Lines changed: 24 additions & 24 deletions
Original file line numberDiff line numberDiff line change
@@ -255,31 +255,28 @@ class Network {
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/// MARK: Normalization
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257257
/// assumes all rows are of equal length
258-
/// and divide each column by its max throughout the data set
259-
/// for that column
260-
func normalizeByColumnMax( dataset:inout [[Double]]) {
258+
/// and feature scale each column to be in the range 0 – 1
259+
func normalizeByFeatureScaling(dataset: inout [[Double]]) {
261260
for colNum in 0..<dataset[0].count {
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let column = dataset.map { 0ドル[colNum] }
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let maximum = column.max()!
263+
let minimum = column.min()!
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for rowNum in 0..<dataset.count {
265-
dataset[rowNum][colNum] = dataset[rowNum][colNum] /maximum
265+
dataset[rowNum][colNum] = (dataset[rowNum][colNum] - minimum)/(maximum- minimum)
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}
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}
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}
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270270
// MARK: Iris Test
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272-
var network: Network = Network(layerStructure: [4,6,3], learningRate: 0.3)
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var irisParameters: [[Double]] = [[Double]]()
274-
var irisClassifications: [[Double]] = [[Double]]()
275-
var irisSpecies: [String] = [String]()
276-
277-
func parseIrisCSV() {
278-
let myBundle = Bundle.main
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let urlpath = myBundle.path(forResource: "iris", ofType: "csv")
272+
func parseIrisCSV() -> (parameters: [[Double]], classifications: [[Double]], species: [String]) {
273+
let urlpath = Bundle.main.path(forResource: "iris", ofType: "csv")
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let url = URL(fileURLWithPath: urlpath!)
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let csv = try! String.init(contentsOf: url)
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let lines = csv.components(separatedBy: "\n")
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var irisParameters: [[Double]] = [[Double]]()
278+
var irisClassifications: [[Double]] = [[Double]]()
279+
var irisSpecies: [String] = [String]()
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let shuffledLines = lines.shuffled()
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for line in shuffledLines {
@@ -297,10 +294,15 @@ func parseIrisCSV() {
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}
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irisSpecies.append(species)
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}
300-
normalizeByColumnMax(dataset: &irisParameters)
297+
normalizeByFeatureScaling(dataset: &irisParameters)
298+
return (irisParameters, irisClassifications, irisSpecies)
301299
}
302300

303-
func interpretOutput(output: [Double]) -> String {
301+
let (irisParameters, irisClassifications, irisSpecies) = parseIrisCSV()
302+
303+
var irisNetwork: Network = Network(layerStructure: [4,6,3], learningRate: 0.3)
304+
305+
func irisInterpretOutput(output: [Double]) -> String {
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if output.max()! == output[0] {
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return "Iris-setosa"
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} else if output.max()! == output[1] {
@@ -310,20 +312,18 @@ func interpretOutput(output: [Double]) -> String {
310312
}
311313
}
312314

313-
// Put setup code here. This method is called before the invocation of each test method in the class.
314-
parseIrisCSV()
315315
// train over first 140 irises in data set 20 times
316-
let trainers = Array(irisParameters[0..<140])
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let trainersCorrects = Array(irisClassifications[0..<140])
316+
let irisTrainers = Array(irisParameters[0..<140])
317+
let irisTrainersCorrects = Array(irisClassifications[0..<140])
318318
for _ in 0..<20 {
319-
network.train(inputs: trainers, expecteds: trainersCorrects, printError: false)
319+
irisNetwork.train(inputs: irisTrainers, expecteds: irisTrainersCorrects, printError: false)
320320
}
321321

322322
// test over the last 10 of the irses in the data set
323-
let testers = Array(irisParameters[140..<150])
324-
let testersCorrects = Array(irisSpecies[140..<150])
325-
let results = network.validate(inputs: testers, expecteds: testersCorrects, interpretOutput: interpretOutput)
326-
print("\(results.correct) correct of \(results.total) = \(results.percentage * 100)%")
323+
let irisTesters = Array(irisParameters[140..<150])
324+
let irisTestersCorrects = Array(irisSpecies[140..<150])
325+
let irisResults = irisNetwork.validate(inputs: irisTesters, expecteds: irisTestersCorrects, interpretOutput: irisInterpretOutput)
326+
print("\(irisResults.correct) correct of \(irisResults.total) = \(irisResults.percentage * 100)%")
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328328
/// Wine Test
329329

@@ -358,7 +358,7 @@ print("\(results.correct) correct of \(results.total) = \(results.percentage * 1
358358
// }
359359
// wineCultivars.append(species)
360360
// }
361-
// normalizeByColumnMax(dataset: &wineParameters)
361+
// normalizeByFeatureScaling(dataset: &wineParameters)
362362
// wineSamples = Array(wineParameters.dropFirst(150))
363363
// wineCultivars = Array(wineCultivars.dropFirst(150))
364364
// wineParameters = Array(wineParameters.dropLast(28))

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