static func formatFloat(float: Float?, withMaxDigits
max: Int, andUnit unit: String) -> String {

            var label: String = "-"

            if let float = float {

                let numberFormatter = NSNumberFormatter()
                numberFormatter.numberStyle = NSNumberFormatterStyle.DecimalStyle
                numberFormatter.minimumFractionDigits = 0
                numberFormatter.maximumFractionDigits = max
                numberFormatter.roundingMode = .RoundHalfUp

                if !float.isNaN {
                    var formattedValue = numberFormatter.stringFromNumber(float)!
                    if(formattedValue == "-0")
                    {
                        formattedValue = "0"
                    }
                    label = "(formattedValue) (unit)"
                }
            }

            return label
        }