/**
* Cosine function.
*
* @param x Argument.
* @return cos(x)
*/
public static double Calc(double x)
{
int quadrant = 0;
/* Take absolute value of the input */
double xa = x;
if (x < 0)
{
xa = -xa;
}
if (xa == double.PositiveInfinity)
{
return(Double.NaN);
}
/* Perform any argument reduction */
double xb = 0;
if (xa > 3294198.0)
{
// PI * (2**20)
// Argument too big for CodyWaite reduction. Must use
// PayneHanek.
double[] reduceResults = new double[3];
PayneHanek.Reduce(xa, reduceResults);
quadrant = ((int)reduceResults[0]) & 3;
xa = reduceResults[1];
xb = reduceResults[2];
}
else if (xa > 1.5707963267948966)
{
CodyWaite cw = new CodyWaite(xa);
quadrant = cw.getK() & 3;
xa = cw.getRemA();
xb = cw.getRemB();
}
//if (negative)
// quadrant = (quadrant + 2) % 4;
switch (quadrant)
{
case 0:
return(cosQ(xa, xb));
case 1:
return(-sinQ(xa, xb));
case 2:
return(-cosQ(xa, xb));
case 3:
return(sinQ(xa, xb));
default:
return(Double.NaN);
}
}
/**
* Tangent function.
*
* @param x Argument.
* @return tan(x)
*/
public static double Calc(double x)
{
bool negative = false;
int quadrant = 0;
/* Take absolute value of the input */
double xa = x;
if (x < 0)
{
negative = true;
xa = -xa;
}
/* Check for zero and negative zero */
if (xa == 0.0)
{
long bits = BitConverter.DoubleToInt64Bits(x);
if (bits < 0)
{
return(-0.0);
}
return(0.0);
}
if (xa == Double.PositiveInfinity)
{
return(Double.NaN);
}
/* Perform any argument reduction */
double xb = 0;
if (xa > 3294198.0)
{
// PI * (2**20)
// Argument too big for CodyWaite reduction. Must use
// PayneHanek.
double[] reduceResults = new double[3];
PayneHanek.Reduce(xa, reduceResults);
quadrant = ((int)reduceResults[0]) & 3;
xa = reduceResults[1];
xb = reduceResults[2];
}
else if (xa > 1.5707963267948966)
{
CodyWaite cw = new CodyWaite(xa);
quadrant = cw.getK() & 3;
xa = cw.getRemA();
xb = cw.getRemB();
}
if (xa > 1.5)
{
// Accuracy suffers between 1.5 and PI/2
double pi2a = 1.5707963267948966;
double pi2b = 6.123233995736766E-17;
double a = pi2a - xa;
double b = -(a - pi2a + xa);
b += pi2b - xb;
xa = a + b;
xb = -(xa - a - b);
quadrant ^= 1;
negative ^= true;
}
double result;
if ((quadrant & 1) == 0)
{
result = Quadrant(xa, xb, false);
}
else
{
result = -Quadrant(xa, xb, true);
}
if (negative)
{
result = -result;
}
return(result);
}
/**
* Sine function.
*
* @param x Argument.
* @return sin(x)
*/
public static double Calc(double x)
{
bool negative = false;
int quadrant = 0;
double xa;
double xb = 0.0;
/* Take absolute value of the input */
xa = x;
if (x < 0)
{
negative = true;
xa = -xa;
}
/* Check for zero and negative zero */
if (xa == 0.0)
{
long bits = BitConverter.DoubleToInt64Bits(x);
if (bits < 0)
{
return(-0.0);
}
return(0.0);
}
if (xa == Double.PositiveInfinity)
{
return(Double.NaN);
}
/* Perform any argument reduction */
if (xa > 3294198.0)
{
// PI * (2**20)
// Argument too big for CodyWaite reduction. Must use
// PayneHanek.
double[] reduceResults = new double[3];
PayneHanek.Reduce(xa, reduceResults);
quadrant = ((int)reduceResults[0]) & 3;
xa = reduceResults[1];
xb = reduceResults[2];
}
else if (xa > 1.5707963267948966)
{
CodyWaite cw = new CodyWaite(xa);
quadrant = cw.getK() & 3;
xa = cw.getRemA();
xb = cw.getRemB();
}
if (negative)
{
quadrant ^= 2; // Flip bit 1
}
switch (quadrant)
{
case 0:
return(Quadrant(xa, xb));
case 1:
return(Cosine.Quadrant(xa, xb));
case 2:
return(-Quadrant(xa, xb));
case 3:
return(-Cosine.Quadrant(xa, xb));
default:
return(Double.NaN);
}
}