code: function(value, unit) {
      // initialize defaults
      this.value = 0
      this.unit  = unit || ''
  
      // parse value
      if (typeof value === 'number') {
        // ensure a valid numeric value
        this.value = isNaN(value) ? 0 : !isFinite(value) ? (value < 0 ? -3.4e+38 : +3.4e+38) : value
  
      } else if (typeof value === 'string') {
        unit = value.match(SVG.regex.numberAndUnit)
  
        if (unit) {
          // make value numeric
          this.value = parseFloat(unit[1])
  
          // normalize
          if (unit[5] == '%')
            this.value /= 100
          else if (unit[5] == 's')
            this.value *= 1000
  
          // store unit
          this.unit = unit[5]
        }
  
      } else {
        if (value instanceof SVG.Number) {
          this.value = value.valueOf()
          this.unit  = value.unit
        }
      }
  
    }
docs: Initialize