func MinInt(values ...int) (min int) {
	if len(values) == 0 {
		return
	}
	min = values[0]
	var value int
	for index := 1; index < len(values); index++ {
		value = values[index]
		if value < min {
			min = value
		}
	}
	return
}
MinInt returns the minimum int.
package chart
import "math"
const (
	_pi   = math.Pi
	_2pi  = 2 * math.Pi
	_3pi4 = (3 * math.Pi) / 4.0
	_4pi3 = (4 * math.Pi) / 3.0
	_3pi2 = (3 * math.Pi) / 2.0
	_5pi4 = (5 * math.Pi) / 4.0
	_7pi4 = (7 * math.Pi) / 4.0
	_pi2  = math.Pi / 2.0
	_pi4  = math.Pi / 4.0
	_d2r  = (math.Pi / 180.0)
	_r2d  = (180.0 / math.Pi)
)
func MinMax(values ...float64) (min, max float64) {
	if len(values) == 0 {
		return
	}
	max = values[0]
	min = values[0]
	var value float64
	for index := 1; index < len(values); index++ {
		value = values[index]
		if value < min {
			min = value
		}
		if value > max {
			max = value
		}
	}
	return
}