62 lines
1.2 KiB
Go
62 lines
1.2 KiB
Go
package main
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import "math"
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func Jaro(a, b string) float64 {
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la := float64(len(a))
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lb := float64(len(b))
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// match range = max(len(a), len(b)) / 2 - 1
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matchRange := int(math.Floor(math.Max(la, lb)/2.0)) - 1
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matchRange = int(math.Max(0, float64(matchRange-1)))
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var matches, halfs float64
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transposed := make([]bool, len(b))
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for i := 0; i < len(a); i++ {
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start := int(math.Max(0, float64(i-matchRange)))
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end := int(math.Min(lb-1, float64(i+matchRange)))
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for j := start; j <= end; j++ {
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if transposed[j] {
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continue
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}
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if a[i] == b[j] {
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if i != j {
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halfs++
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}
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matches++
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transposed[j] = true
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break
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}
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}
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}
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if matches == 0 {
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return 0
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}
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transposes := math.Floor(float64(halfs / 2))
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return ((matches / la) + (matches / lb) + (matches-transposes)/matches) / 3.0
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}
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func JaroWinkler(a, b string, boostThreshold float64, prefixSize int) float64 {
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j := Jaro(a, b)
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if j <= boostThreshold {
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return j
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}
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prefixSize = int(math.Min(float64(len(a)), math.Min(float64(prefixSize), float64(len(b)))))
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var prefixMatch float64
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for i := 0; i < prefixSize; i++ {
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if a[i] == b[i] {
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prefixMatch++
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}
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}
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return j + 0.1*prefixMatch*(1.0-j)
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} |