116 lines
2 KiB
Go
116 lines
2 KiB
Go
package gago
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import (
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"math"
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)
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func newInts(n int) []int {
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var ints = make([]int, n)
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for i := range ints {
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ints[i] = i
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}
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return ints
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}
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// Divide each element in a float64 slice by a given value.
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func divide(floats []float64, value float64) []float64 {
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var divided = make([]float64, len(floats))
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for i, v := range floats {
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divided[i] = v / value
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}
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return divided
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}
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// Compute the cumulative sum of a float64 slice.
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func cumsum(floats []float64) []float64 {
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var summed = make([]float64, len(floats))
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copy(summed, floats)
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for i := 1; i < len(summed); i++ {
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summed[i] += summed[i-1]
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}
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return summed
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}
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// Find the minimum between two ints.
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func min(a, b int) int {
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if a <= b {
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return a
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}
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return b
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}
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// Compute the sum of an int slice.
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func sumInts(ints []int) (sum int) {
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for _, v := range ints {
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sum += v
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}
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return
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}
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// Compute the sum of a float64 slice.
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func sumFloat64s(floats []float64) (sum float64) {
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for _, v := range floats {
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sum += v
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}
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return
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}
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// Compute the minimum value of a float64 slice.
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func minFloat64s(floats []float64) (min float64) {
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min = math.Inf(1)
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for _, f := range floats {
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if f < min {
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min = f
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}
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}
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return
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}
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// Compute the maximum value of a float64 slice.
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func maxFloat64s(floats []float64) (max float64) {
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max = math.Inf(-1)
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for _, f := range floats {
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if f > max {
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max = f
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}
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}
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return
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}
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// Compute the mean of a float64 slice.
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func meanFloat64s(floats []float64) float64 {
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return sumFloat64s(floats) / float64(len(floats))
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}
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// Compute the variance of a float64 slice.
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func varianceFloat64s(floats []float64) float64 {
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var (
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m = meanFloat64s(floats)
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ss float64
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)
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for _, x := range floats {
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ss += math.Pow(x-m, 2)
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}
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return ss / float64(len(floats))
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}
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type set map[interface{}]bool
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// union merges two slices and ignores duplicates.
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func union(x, y set) set {
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var (
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u = make(set)
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blackList = make(map[interface{}]bool)
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)
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for i := range x {
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u[i] = true
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blackList[i] = true
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}
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for i := range y {
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if !blackList[i] {
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u[i] = true
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blackList[i] = true
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}
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}
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return u
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}
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