go-chart/util.go
2016-07-07 17:14:25 -07:00

69 lines
1.3 KiB
Go

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