Found a 64bit double implementation library, but I cannot compile it

Projects Programming
22

thanks everybody, here the solution I'm using:

BigNumber sine (BigNumber x, BigNumber p)
{
  while (x > doublePI){//stay in range!
     x -= doublePI;
  }
  
  while (x < 0){//stay in range!
     x += doublePI;
  }
  
  BigNumber one = 1;
  BigNumber two = 2;
  BigNumber val = one;

  while (p > 0)
  {
    val = one - val * x * x / (two * p) / (two * p + one);
    p = p - one;
  }
  val = x * val;
  return val;
} // end of sine

BigNumber cosine (BigNumber x, BigNumber p)
{
  return sine(x+halfPI, p);
}  // end of cosine

BigNumber tangent (BigNumber x, BigNumber p)
{
  return (sine (x, p) / sine (x+halfPI, p));
} // end of tangent

note you will need halfPI and doublePI:

BigNumber::begin ();
  BigNumber::setScale (20);
  bigPI = BigNumber ("3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706");
  halfPI = bigPI;
  halfPI /= 2;
  doublePI = bigPI;
  doublePI *= 2;

now i'm going to test the real duration of my code at different precision, i'll post here the code and the results. thanks again everybody!!!

edit: it's a honour to talk with the man who wrote this lib. just a little problem (arduino IDE 1.0.1):

halfPI = PI / 2;

give some error with overloaded constructor. I've work around it because I'm not good with c++ :grin: