/// <summary>
/// Returns a random double from the full range of possible double values.
/// The sign, mantissa and the exponent are independent random numbers,
/// thus the distribution of numbers is not uniform.
/// </summary>
/// <returns></returns>
public double NextDoubleFullRange()
{
long mantissa = NextLong(52);
int exponent = _random.Next(-1023-52, 1024-52);
int sign = NextBool() ? -1 : +1; // Gets us -1 or +1.
double result = sign * (double)mantissa * (double)Math.Pow(2.0, exponent);
var dc = new DoubleComponents(result);
Debug.Assert(result == dc.CalcValue());
return result;
}
/// <summary>
/// Returns a random double from the full range of possible double values.
/// The sign, mantissa and the exponent are independent random numbers,
/// thus the distribution of numbers is not uniform.
/// </summary>
/// <returns></returns>
public double NextDoubleFullRange()
{
long mantissa = NextLong(52);
int exponent = _random.Next(-1023 - 52, 1024 - 52);
int sign = NextBool() ? -1 : +1; // Gets us -1 or +1.
double result = sign * (double)mantissa * (double)Math.Pow(2.0, exponent);
var dc = new DoubleComponents(result);
Debug.Assert(result == dc.CalcValue());
return(result);
}
// Returns a double in the range where we expect the robust arithmetic to be valid
// - exponents between -142 and 201. (According to S. p.3)
public double NextDoubleValidRange()
{
double result = double.NaN;
while (!(result.IsNumber() && result.IsInRange()))
{
long mantissa = NextLong(52);
int exponent = _random.Next(-1023 - 52, 1024 - 52);
int sign = NextBool() ? -1 : +1; // Gets us -1 or +1.
result = sign * (double)mantissa * (double)Math.Pow(2.0, exponent);
var dc = new DoubleComponents(result);
Debug.Assert(result == dc.CalcValue());
}
return result;
}
// Returns a double in the range where we expect the robust arithmetic to be valid
// - exponents between -142 and 201. (According to S. p.3)
public double NextDoubleValidRange()
{
double result = double.NaN;
while (!(result.IsNumber() && result.IsInRange()))
{
long mantissa = NextLong(52);
int exponent = _random.Next(-1023 - 52, 1024 - 52);
int sign = NextBool() ? -1 : +1; // Gets us -1 or +1.
result = sign * (double)mantissa * (double)Math.Pow(2.0, exponent);
var dc = new DoubleComponents(result);
Debug.Assert(result == dc.CalcValue());
}
return(result);
}
