document.write("numerics.js running \n");

afunct(2, 3.29);

function print2d(M)
{
  var n = M.length;
  var m = M[0].length;
  document.write("M.length = "+n+", by width ="+m+" \n");
  for(var i=0; i<n; i++)
  {
    for(var j=0; j<m; j++)
    {
      document.write("M["+i+"]["+j+"]="+M[i][j]+" \n");
    }
  }
} // end print2d

function afunct(x,y)
{
  var z=1.1;
  document.write("in afunct \n");
  document.write("x = "+x+" \n");
  document.write("y = "+y+" \n");
  document.write("z=Math.floor(y)="+Math.floor(y)+" \n");
  document.write("z=Math.ceil(y)="+Math.ceil(y)+" \n");
  document.write("z=Math.round(y)="+Math.round(y)+" \n");
  document.write("z=Math.max(x,y)="+Math.max(x,y)+" \n");
  document.write("z=Math.min(x,y)="+Math.min(x,y)+" \n");
  document.write("z=Math.sqrt(y)="+Math.sqrt(y)+" \n");
  document.write("z=Math.sin(y)="+Math.sin(y)+" \n");
  document.write("z=Math.cos(y)="+Math.cos(y)+" \n");
  document.write("z=Math.tan(y)="+Math.tan(y)+" \n");
  document.write("z=Math.asin(0.5)="+Math.asin(0.5)+" \n");
  document.write("z=Math.acos(0.5)="+Math.acos(0.5)+" \n");
  document.write("z=Math.atan(0.5)="+Math.atan(0.5)+" \n");
  document.write("z=Math.exp(y)="+Math.exp(y)+" \n");
  document.write("z=Math.log(y)="+Math.log(y)+" \n");

  if(x==y) // != < > <+ >+ 
  {
    document.write("if(x==y) \n");
  }
  else if(x<y)
  {
    document.write("if(x&lt;y) \n");
  }

  var A = new Array(); // or just  A = new Array();
  document.write("A=new Array() \n");
  document.write("for(var i=0; i<3; i++) \n");
  for(var i=0; i<3; i++)
  {
    A[A.length] = 2*i;
  }
  for(var i=0; i<A.length; i++)
  {
    document.write("A["+i+"]="+A[i]+"\n");
  }
  B = new Array(1, 2, 3, 5, 8, 13);
  B.pop();
  B.pop();
  B.push(88,1313); // can be multiple items
  for(var i=0; i<B.length; i++)
  {
    document.write("B["+i+"]="+B[i]+"\n");
  }
  C = ["a", "b", "c", "d", "e"]; // not { }
  document.write(C[0]+C[1]+C[2]+C[3]+C[4]+"\n");
  C = C.slice(1,4); // i=1, i<4, i++
  document.write("C.length="+C.length+" C[C.length-1]="+C[C.length-1]+"\n");
  document.write(C[0]+C[1]+C[2]+"\n");

  document.write("two dimensional array \n");
  var AA = new Array();
  for(var i=0; i<4; i++)
  {
    AA[i] = new Array();
    for(var j=0; j<4; j++)
    {
      AA[i][j]=i+j;
    }
    document.write(AA[i][0]+" "+AA[i][1]+" "+AA[i][2]+" "+AA[i][3]+"\n");
  }
  print2d(AA);

  document.write("leaving afunct \n");
}