code: function ( o ) {
  
          this.isNumber = true;
  
          this.value = 0;
          if(o.value !== undefined){
              if( typeof o.value === 'string' ) this.value = o.value * 1;
              else this.value = o.value;
          }
  
          this.min = o.min === undefined ? -Infinity : o.min;
          this.max = o.max === undefined ?  Infinity : o.max;
          this.precision = o.precision === undefined ? 2 : o.precision;
  
          var s;
  
          switch(this.precision){
              case 0: s = 1; break;
              case 1: s = 0.1; break;
              case 2: s = 0.01; break;
              case 3: s = 0.001; break;
              case 4: s = 0.0001; break;
          }
  
          this.step = o.step === undefined ?  s : o.step;
          this.range = this.max - this.min;
          this.value = this.numValue( this.value );
          
      }
docs: ---------------------- for numeric value ----------------------