/*This script is the property of MatWeb.com.  This code may
  not be copied without the express written consent of MatWeb.com.
  Author: Tiffany Tibbs email: tiffany@matweb.com*/

  var unitsM='grams';
  var unitsE='pounds';
  var unitsMOI='g/cm2';

  function CalculateWeight(f,n){
    var density
    var quantity
    var dims=new Array(5);
    var Units=new Array(5);
    var MatlSelect;
    var Shape;
    var weightM=new Number(0);
    var weightE=new Number(0);
    var pi=new Number(3.141592654);
    var moiX=new Number(0);
    var moiY=new Number(0);

    MatlSelect=f.material.selectedIndex;
    if(MatlSelect=="0"){
      density=f.density.value;
      Units[0]=f.units0.options[f.units0.selectedIndex].value;
      }
    else{
      density=f.material.options[f.material.selectedIndex].value;
      Units[0]=0;
      }

    density=DensityConverter(density,Units[0],'/');
    if(!CheckVal(density, 'Density', f.density)) return;
    quantity=f.qty.value;
    if(!CheckVal(quantity, 'Quantity', f.qty)) return;
    quantity=UnitConverter(quantity,"cm");

    for(var i=1;i<=n;i++){
      f.elements['value'+i].value=trim(f.elements['value'+i].value);
      if(!CheckVal(f.elements['value'+i].value, 'All dimensions', f.elements['value'+i])) return;
      dims[i]=f.elements['value'+i].value
      Units[i]=f.elements['units'+i].options[f.elements['units'+i].selectedIndex].text;
      dims[i]=UnitConverter(dims[i],Units[i]);
      }

    Shape=f.shape.selectedIndex;

    //
    //
    // all formulas were taken from
    // Roark's Formulas for Stress & Strain
    // pp 62 - 72
    //

    if(Shape=="0"){ //Rectangle
      weightM=(density * dims[1] * dims[2] * dims[3]);
      var d=new Number(dims[1]);
      var b=new Number(dims[2]);
      moiX=b*Math.pow(d,3)/12;
      moiY=d*Math.pow(b,3)/12;
      }
    if(Shape=="1"){ //Square
      weightM=(density * dims[1] * dims[1] * dims[2]);
      var a=new Number(dims[1]);
      moiX=Math.pow(a,4)/12;
      moiY=Math.pow(a,4)/12;
      }
    if(Shape=="2"){ //Hexagon 1
      var A=new Number(0.64952 * dims[1] * dims[1] * dims[2]);
      weightM=(density * A);
      var a =new Number(dims[1]/2); // for this shape, a is same as radius
      var r1=new Number(dims[1]/2); // outer diameter
      moiX=(A*(6*Math.pow(r1,2)-Math.pow(a,2)))/24;
      moiY=(A*(6*Math.pow(r1,2)-Math.pow(a,2)))/24;
      }
    if(Shape=="3"){ //Hexagon 2
      var A=new Number(0.86602 * dims[1] * dims[1] * dims[2]);
      weightM=(density * A);
      var r2=new Number(dims[1]/2);
      var r1=new Number((r2)/Math.cos(30*pi/180));
      var a =new Number(r1); // for this shape, a is same as r1
      moiX=(A*(6*Math.pow(r1,2)-Math.pow(a,2)))/24;
      moiY=(A*(6*Math.pow(r1,2)-Math.pow(a,2)))/24;
      }
    if(Shape=="4"){ //Octagon 1
      var A=new Number(0.707327 * dims[1] * dims[1] * dims[2]);
      weightM=(density * A);
      var r1=new Number(dims[1]/2); // outer diameter
      var a =new Number(2*r1*Math.sin(22.5*pi/180));
      moiX=(A*(6*Math.pow(r1,2)-Math.pow(a,2)))/24;
      moiY=(A*(6*Math.pow(r1,2)-Math.pow(a,2)))/24;
      }
    if(Shape=="5"){ //Octagon 2
      var A=new Number(0.82842 * dims[1] * dims[1] * dims[2]);
      weightM=(density * A);
      var r2=new Number(dims[1]/2); // inner diameter
      var r1=new Number((r2)/Math.cos(22.5*pi/180));
      var a =new Number(2*r1*Math.sin(22.5*pi/180));
      moiX=(A*(6*Math.pow(r1,2)-Math.pow(a,2)))/24;
      moiY=(A*(6*Math.pow(r1,2)-Math.pow(a,2)))/24;
      }
    if(Shape=="6"){ //Circle
      weightM=(density * 0.785398 * dims[1] * dims[1] * dims[2]);
      var r=new Number(dims[1]/2);
      moiX=pi/4*Math.pow(r,4);
      moiY=pi/4*Math.pow(r,4);
      }
    if(Shape=="7"){ //Tube
      weightM=(density * 0.785398 * ((dims[1] * dims[1]) - (dims[2] * dims[2])) * dims[3]);
      var r1=new Number(dims[1]/2);
      var r2=new Number(dims[2]/2);
      moiX=pi/4*(Math.pow(r1,4) - Math.pow(r2,4));
      moiY=pi/4*(Math.pow(r1,4) - Math.pow(r2,4));
      }
    if(Shape=="8"){ //I-Beam
      weightM=(density * (2 * dims[1] * dims[2] + dims[3] * dims[4]) * dims[5]);
      var b =new Number(dims[1]);
      var d =new Number(dims[3]);
      var t1=new Number(dims[2]);
      var t2=new Number(dims[4]);
      moiX=b*Math.pow(d+2*t1,3)/12 + (b-t2)*Math.pow(d,3)/12;
      moiY=Math.pow(b,3)*t1/6 + Math.pow(t2,3)*d/12;
      }
    if(Shape=="9"){ //Angle Iron
      weightM=(density * dims[1] * (2 * dims[2] - dims[1]) * dims[3]);
      var a=new Number(dims[2]);
      var t=new Number(dims[1]);
      var b=new Number(a-t);
      moiX=(Math.pow(a,4)-Math.pow(b,4))/12 - .5*t*Math.pow(a,2)*Math.pow(b,2)/(a+b);
      moiY=(Math.pow(a,4)-Math.pow(b,4))/12;
      }
    if(Shape=="10"){ //hollow Rectangle
      weightM=density * ((dims[1] * dims[2]) - (dims[3] * dims[4])) * dims[5];
      var d1=new Number(dims[1]);
      var b1=new Number(dims[2]);
      var d2=new Number(dims[3]);
      var b2=new Number(dims[4]);
      moiX=(b1*Math.pow(d1,3) - b2*Math.pow(d2,3))/12;
      moiY=(d1*Math.pow(b1,3) - d2*Math.pow(b2,3))/12;
      }
    if(Shape=="11"){ //tee section
      weightM=(density * (dims[1] * dims[2] + dims[3] * dims[4]) * dims[5]);
      var b =new Number(dims[1]);
      var t1=new Number(dims[2]);
      var d =new Number(dims[3]);
      var t2=new Number(dims[4]);
      var A =new Number(b*t1+d*t2);
      var Y1=new Number((b*Math.pow(t1,2)+t2*d*(2*t1+d))/(2*(t1*b+t2*d)));
      moiX=b/3*Math.pow(d+t1,3) - Math.pow(d,3)*(b-t2)/3 - A*Math.pow(d+t1-Y1,2);
      moiY=t1+Math.pow(b,3)/12 + d*Math.pow(t2,3)/12
      }
    if(Shape=="12"){ //U channel
      weightM=(density * (dims[1] * dims[2] + 2 * (dims[3] * dims[4])) * dims[5]);
      var b =new Number(dims[1]);
      var t1=new Number(dims[2]);
      var d =new Number(dims[3]);
      var t2=new Number(dims[4]);
      var A =new Number(b*t1+2*(d*t2));
      var Y1=new Number((b*Math.pow(t1,2)+2*t2*d*(2*t1+d))/(2*(t1*b+2*t2*d)));
      moiX=b/3*Math.pow(d+t1,3) - Math.pow(d,3)*(b-2*t2)/3 - A*Math.pow(d+t1-Y1,2);
      moiY=(d+t1)*Math.pow(b,3)/12 - d*Math.pow(b-2*t2,3)/12
      }
    if(Shape=="13"){ //N sided Polygon
      var n =new Number(dims[1]);
      var a =new Number(dims[2]);
      var an=new Number((360/(n*2))*pi/180);
      var r1=a/(2*Math.sin(an));
      var r2=a/(2*Math.tan(an));
      var A =new Number((Math.pow(a,2)*n)/(4*Math.tan(an)));
      weightM=density * A * dims[3];
      moiX=(A*(6*Math.pow(r1,2)-Math.pow(a,2)))/24;
      moiY=(A*(6*Math.pow(r1,2)-Math.pow(a,2)))/24;
      }
    //alert('r1='+r1+'\nr2='+r2+'\na='+a);

    //Converting weightM to weightE(pounds)
    weightE=weightM*0.002205;

    f.weightM.value=roundIt(weightM*quantity,'M')+' '+unitsM;
    f.weightE.value=roundIt(weightE*quantity,'E')+' '+unitsE;
    //alert(moiX);
    //alert(moiY);
    if(f.moiX!=null){
      f.moiX.value=roundIt(moiX,'M')+' '+unitsMOI;
      f.moiY.value=roundIt(moiY,'M')+' '+unitsMOI;
      }
    }

  function roundIt(v,units){
    unitsM='grams';
    unitsE='pounds';
    unitsMOI='cm4';
    //alert(v);

    if(v>=1000){
      //convert to Kg & round
      if(units=='M'){
        unitsM='kilograms';
        unitsMOI='m4';
        return Math.round(v/1000*10000)/10000;
        }
      else
        return Math.round(v*1000)/1000;
      }
    if((v<1000)&&(v>=0.0001)){
      //Rounding value
      return Math.round(v*10000)/10000;
      }

    if(v<0.0001){
      //Rounding small value
      return Math.round(v*100000000)/100000000;
      }
    }

  function CheckVal(v, t, ctl){
    if((v=="" || isNaN(v) || v<0)){
      alert(t+" must have a positive numeric value to calculate total weight.");
      ctl.focus();
      ctl.select();
      return false;
      }
    return true;
    }

  function Default(f,dims){
    f.material.selectedIndex="0";
    f.density.value="";
    f.units0.selectedIndex="0";
    f.qty.value="1";
    for(var i=1;i<=dims;i++){
      f.elements['value'+i].value="";
      f.elements['units'+i].selectedIndex=1;
      }
    f.weightM.value='';
    f.weightE.value='';
    }

  function setDensity(f){
    f.density.value=f.material.options[f.material.selectedIndex].value;
    f.units0.selectedIndex="0";
    }

  function DensityConverter(value,unit,oper){
    if(unit==0)
      value=eval('value'+oper+'1');
    if(unit==1)
      value=eval('value'+oper+'0.03613');
    if(unit==2)
      value=eval('value'+oper+'62.42797');
    if(unit==3)
      value=eval('value'+oper+'1000');
    return value;
    }

  function UnitChange(f){
    var MatlSelect;
    var Units;
    var Density;
    var Converted;

    MatlSelect=f.material.selectedIndex;

    if(MatlSelect!="0"){
      Units=f.units0.selectedIndex;
      Density=f.material.options[f.material.selectedIndex].value;
      Converted=DensityConverter(Density,Units,'*');
      f.density.value=Converted;
      }
    }

  function UnitConverter(value,unit){
    if(unit=="mm")
      value=value/10;
    if(unit=="m")
      value=value*100;
    if(unit=="in")
      value=value*2.54;
    if(unit=="ft")
      value=(value*2.54)*12;
    if(unit=="yd")
      value=(value*2.54)*36;
    return value;
    }

  function trim(s)  { return ltrim(rtrim(s)) }
  function ltrim(s) { return s.replace(/^\s+/g, "") }
  function rtrim(s) { return s.replace(/\s+$/g, "") }