static bool NonOverlaps(this double x, double y)
{
// Check non-number flags
if (!x.IsNumber())
{
throw new ArgumentOutOfRangeException("x");
}
if (!y.IsNumber())
{
throw new ArgumentOutOfRangeException("y");
}
// Special case for 0:
// Shewchuk p3: "The number zero does not overlap any number."
if (x == 0.0 || y == 0.0)
{
return(true);
}
// Break into components
var xc = new DoubleComponents(x);
// We now have that x = xc.Mantissa * 2 ^ xc.Exponent
// Normalize - this writes x = r.2^s with the maximal exponent s
xc.MaximizeExponent();
// now compare abs of y with 2^s
return((double)Math.Abs(y) < (double)(Math.Pow(2.0, xc.Exponent)));
}
public static bool IsPowerOfTwo(this double d)
{
var dc = new DoubleComponents(d);
dc.MaximizeExponent();
return(dc.Mantissa == 1);
}
/// <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);
}
/// <summary>
/// Formats a double as a floating point binary string, e.g. 0.25 -> 0.01
/// </summary>
/// <param name="d"></param>
/// <returns></returns>
/// <example>4 = 1.2^2 -> 100
/// 0.25 = 1.2^-2 -> 0.01
/// </example>
public static string ToFloatingPointBinaryString(this double d)
{
var dc = new DoubleComponents(d);
dc.MaximizeExponent();
var revChars = new List <char>();
while (dc.Exponent < 0)
{
revChars.Add(((dc.Mantissa & 1L) == 1L) ? '1' : '0');
dc.Exponent++;
dc.Mantissa >>= 1;
}
revChars.Add('.');
// Write out 0s as long as the exponent suggests
while (dc.Exponent > 0)
{
revChars.Add('0');
dc.Exponent--;
}
// write out the rest of the Mantissa
while (dc.Mantissa != 0L)
{
revChars.Add(((dc.Mantissa & 1L) == 1L) ? '1' : '0');
dc.Mantissa >>= 1;
}
// Before we reverse - add a '0' to the end (which will go in front) if needed
if (revChars.Last() == '.')
{
revChars.Add('0');
}
// Prepend the sign (by adding before we reverse)
if (dc.Negative)
{
revChars.Add('-');
}
revChars.Reverse();
// Now a '0' after the '.' if needed (alternative would be to strip to '.')
if (revChars.Last() == '.')
{
revChars.Add('0');
}
return(new string(revChars.ToArray()));
}
// 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);
}
static bool NonOverlaps(this double x, double y)
{
// Check non-number flags
if (!x.IsNumber()) throw new ArgumentOutOfRangeException("x");
if (!y.IsNumber()) throw new ArgumentOutOfRangeException("y");
// Special case for 0:
// Shewchuk p3: "The number zero does not overlap any number."
if (x == 0.0 || y == 0.0) return true;
// Break into components
var xc = new DoubleComponents(x);
// We now have that x = xc.Mantissa * 2 ^ xc.Exponent
// Normalize - this writes x = r.2^s with the maximal exponent s
xc.MaximizeExponent();
// now compare abs of y with 2^s
return (double)Math.Abs(y) < (double)(Math.Pow(2.0, xc.Exponent));
}
public static bool IsPowerOfTwo(this double d)
{
var dc = new DoubleComponents(d);
dc.MaximizeExponent();
return dc.Mantissa == 1;
}
/// <summary>
/// Formats a double as a floating point binary string, e.g. 0.25 -> 0.01
/// </summary>
/// <param name="d"></param>
/// <returns></returns>
/// <example>4 = 1.2^2 -> 100
/// 0.25 = 1.2^-2 -> 0.01
/// </example>
public static string ToFloatingPointBinaryString(this double d)
{
var dc = new DoubleComponents(d);
dc.MaximizeExponent();
var revChars = new List<char>();
while (dc.Exponent < 0)
{
revChars.Add(((dc.Mantissa & 1L) == 1L) ? '1' : '0');
dc.Exponent++;
dc.Mantissa >>= 1;
}
revChars.Add('.');
// Write out 0s as long as the exponent suggests
while (dc.Exponent > 0)
{
revChars.Add('0');
dc.Exponent--;
}
// write out the rest of the Mantissa
while (dc.Mantissa != 0L)
{
revChars.Add( ((dc.Mantissa & 1L) == 1L) ? '1' : '0');
dc.Mantissa >>= 1;
}
// Before we reverse - add a '0' to the end (which will go in front) if needed
if (revChars.Last() == '.') revChars.Add('0');
// Prepend the sign (by adding before we reverse)
if (dc.Negative) revChars.Add('-');
revChars.Reverse();
// Now a '0' after the '.' if needed (alternative would be to strip to '.')
if (revChars.Last() == '.') revChars.Add('0');
return new string(revChars.ToArray());
}
