73 lines
1.4 KiB
Go
73 lines
1.4 KiB
Go
package chart
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import (
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"fmt"
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"image/color"
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"time"
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)
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// ColorIsZero returns if a color.RGBA is unset or not.
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func ColorIsZero(c color.RGBA) bool {
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return c.R == 0 && c.G == 0 && c.B == 0 && c.A == 0
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}
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// ColorAsString returns if a color.RGBA is unset or not.
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func ColorAsString(c color.RGBA) string {
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a := float64(c.A) / float64(255)
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return fmt.Sprintf("rgba(%v,%v,%v,%.1f)", c.R, c.G, c.B, a)
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}
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// MinAndMax returns both the min and max in one pass.
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func MinAndMax(values ...float64) (min float64, max float64) {
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if len(values) == 0 {
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return
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}
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min = values[0]
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max = values[0]
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for _, v := range values {
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if max < v {
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max = v
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}
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if min > v {
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min = v
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}
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}
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return
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}
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// MinAndMaxOfTime returns the min and max of a given set of times
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// in one pass.
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func MinAndMaxOfTime(values ...time.Time) (min time.Time, max time.Time) {
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if len(values) == 0 {
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return
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}
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min = values[0]
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max = values[0]
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for _, v := range values {
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if max.Before(v) {
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max = v
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}
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if min.After(v) {
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min = v
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}
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}
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return
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}
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// Slices generates N slices that span the total.
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// The resulting array will be intermediate indexes until total.
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func Slices(count int, total float64) []float64 {
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var values []float64
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sliceWidth := float64(total) / float64(count)
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for cursor := 0.0; cursor < total; cursor += sliceWidth {
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values = append(values, cursor)
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}
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return values
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}
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func flf(v float64) string {
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return fmt.Sprintf("%.2f", v)
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}
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