Go :: 格式化浮点数，保留 n 位小数

[dushaoshuai]

round to nearest

func RoundPrecision(x float64, precision int) float64 {
    ratio := math.Pow10(precision)
    return math.Round(x*ratio) / ratio
}

round up

func RoundUpPrecision(x float64, precision int) float64 {
    ratio := math.Pow10(precision)
    return math.Ceil(x*ratio) / ratio
}

round down

func RoundDownPrecision(x float64, precision int) float64 {
    ratio := math.Pow10(precision)
    return math.Floor(x*ratio) / ratio
}