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			128 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
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			128 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| // Copyright ©2016 The Gonum Authors. All rights reserved.
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| // Use of this source code is governed by a BSD-style
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| // license that can be found in the LICENSE file.
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| 
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| package stat_test
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| 
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| import (
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| 	"fmt"
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| 	"math"
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| 
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| 	"gonum.org/v1/gonum/floats"
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| 	"gonum.org/v1/gonum/integrate"
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| 	"gonum.org/v1/gonum/stat"
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| )
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| 
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| func ExampleROC_weighted() {
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| 	y := []float64{0, 3, 5, 6, 7.5, 8}
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| 	classes := []bool{false, true, false, true, true, true}
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| 	weights := []float64{4, 1, 6, 3, 2, 2}
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| 
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| 	tpr, fpr, _ := stat.ROC(nil, y, classes, weights)
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| 	fmt.Printf("true  positive rate: %v\n", tpr)
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| 	fmt.Printf("false positive rate: %v\n", fpr)
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| 
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| 	// Output:
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| 	// true  positive rate: [0 0.25 0.5 0.875 0.875 1 1]
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| 	// false positive rate: [0 0 0 0 0.6 0.6 1]
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| }
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| 
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| func ExampleROC_unweighted() {
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| 	y := []float64{0, 3, 5, 6, 7.5, 8}
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| 	classes := []bool{false, true, false, true, true, true}
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| 
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| 	tpr, fpr, _ := stat.ROC(nil, y, classes, nil)
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| 	fmt.Printf("true  positive rate: %v\n", tpr)
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| 	fmt.Printf("false positive rate: %v\n", fpr)
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| 
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| 	// Output:
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| 	// true  positive rate: [0 0.25 0.5 0.75 0.75 1 1]
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| 	// false positive rate: [0 0 0 0 0.5 0.5 1]
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| }
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| 
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| func ExampleROC_threshold() {
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| 	y := []float64{0.1, 0.4, 0.35, 0.8}
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| 	classes := []bool{false, false, true, true}
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| 	stat.SortWeightedLabeled(y, classes, nil)
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| 
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| 	tpr, fpr, thresh := stat.ROC(nil, y, classes, nil)
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| 	fmt.Printf("true  positive rate: %v\n", tpr)
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| 	fmt.Printf("false positive rate: %v\n", fpr)
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| 	fmt.Printf("cutoff thresholds: %v\n", thresh)
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| 
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| 	// Output:
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| 	// true  positive rate: [0 0.5 0.5 1 1]
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| 	// false positive rate: [0 0 0.5 0.5 1]
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| 	// cutoff thresholds: [+Inf 0.8 0.4 0.35 0.1]
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| }
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| 
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| func ExampleROC_unsorted() {
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| 	y := []float64{8, 7.5, 6, 5, 3, 0}
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| 	classes := []bool{true, true, true, false, true, false}
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| 	weights := []float64{2, 2, 3, 6, 1, 4}
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| 
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| 	stat.SortWeightedLabeled(y, classes, weights)
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| 
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| 	tpr, fpr, _ := stat.ROC(nil, y, classes, weights)
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| 	fmt.Printf("true  positive rate: %v\n", tpr)
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| 	fmt.Printf("false positive rate: %v\n", fpr)
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| 
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| 	// Output:
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| 	// true  positive rate: [0 0.25 0.5 0.875 0.875 1 1]
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| 	// false positive rate: [0 0 0 0 0.6 0.6 1]
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| }
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| 
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| func ExampleROC_knownCutoffs() {
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| 	y := []float64{8, 7.5, 6, 5, 3, 0}
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| 	classes := []bool{true, true, true, false, true, false}
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| 	weights := []float64{2, 2, 3, 6, 1, 4}
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| 	cutoffs := []float64{-1, 3, 4}
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| 
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| 	stat.SortWeightedLabeled(y, classes, weights)
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| 
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| 	tpr, fpr, _ := stat.ROC(cutoffs, y, classes, weights)
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| 	fmt.Printf("true  positive rate: %v\n", tpr)
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| 	fmt.Printf("false positive rate: %v\n", fpr)
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| 
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| 	// Output:
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| 	// true  positive rate: [0.875 0.875 1]
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| 	// false positive rate: [0.6 0.6 1]
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| }
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| 
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| func ExampleROC_equallySpacedCutoffs() {
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| 	y := []float64{8, 7.5, 6, 5, 3, 0}
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| 	classes := []bool{true, true, true, false, true, true}
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| 	weights := []float64{2, 2, 3, 6, 1, 4}
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| 	n := 9
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| 
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| 	stat.SortWeightedLabeled(y, classes, weights)
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| 	cutoffs := make([]float64, n)
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| 	floats.Span(cutoffs, math.Nextafter(y[0], y[0]-1), y[len(y)-1])
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| 
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| 	tpr, fpr, _ := stat.ROC(cutoffs, y, classes, weights)
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| 	fmt.Printf("true  positive rate: %.3v\n", tpr)
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| 	fmt.Printf("false positive rate: %.3v\n", fpr)
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| 
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| 	// Output:
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| 	// true  positive rate: [0 0.333 0.333 0.583 0.583 0.583 0.667 0.667 1]
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| 	// false positive rate: [0 0 0 0 1 1 1 1 1]
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| }
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| 
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| func ExampleROC_aUC() {
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| 	y := []float64{0.1, 0.35, 0.4, 0.8}
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| 	classes := []bool{true, false, true, false}
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| 
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| 	tpr, fpr, _ := stat.ROC(nil, y, classes, nil)
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| 
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| 	// Compute Area Under Curve.
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| 	auc := integrate.Trapezoidal(fpr, tpr)
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| 	fmt.Printf("true  positive rate: %v\n", tpr)
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| 	fmt.Printf("false positive rate: %v\n", fpr)
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| 	fmt.Printf("auc: %v\n", auc)
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| 
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| 	// Output:
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| 	// true  positive rate: [0 0 0.5 0.5 1]
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| 	// false positive rate: [0 0.5 0.5 1 1]
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| 	// auc: 0.25
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| }
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