/// <summary>
/// math.frexp implementation in C#
/// </summary>
/// <param name="value"></param>
/// <returns></returns>
public static FRexpResult frexp(double value)
{
FRexpResult result = new FRexpResult();
long bits = BitConverter.DoubleToInt64Bits(value);
double realMant = 1;
// Test for NaN, infinity, and zero.
if (Double.IsNaN(value) ||
value + value == value ||
Double.IsInfinity(value))
{
result.exponent = 0;
result.mantissa = value;
}
else
{
bool neg = (bits < 0);
int exponent = (int)((bits >> 52) & 0x7ffL);
long mantissa = bits & 0xfffffffffffffL;
if (exponent == 0)
{
exponent++;
}
else
{
mantissa = mantissa | (1L << 52);
}
// bias the exponent - actually biased by 1023.
// we are treating the mantissa as m.0 instead of 0.m
// so subtract another 52.
exponent -= 1075;
realMant = mantissa;
// normalize
while (realMant > 1.0)
{
mantissa >>= 1;
realMant /= 2;
exponent++;
}
if (neg)
{
realMant = realMant * -1;
}
result.exponent = exponent;
result.mantissa = realMant;
}
return(result);
}
/// <summary>
/// math.frexp implementation in C#
/// </summary>
/// <param name="value"></param>
/// <returns></returns>
public static FRexpResult frexp(double value)
{
FRexpResult result = new FRexpResult();
long bits = BitConverter.DoubleToInt64Bits(value);
double realMant = 1;
// Test for NaN, infinity, and zero.
if (Double.IsNaN(value) ||
value + value == value ||
Double.IsInfinity(value))
{
result.exponent = 0;
result.mantissa = value;
}
else
{
bool neg = (bits < 0);
int exponent = (int)((bits >> 52) & 0x7ffL);
long mantissa = bits & 0xfffffffffffffL;
if (exponent == 0)
{
exponent++;
}
else
{
mantissa = mantissa | (1L << 52);
}
// bias the exponent - actually biased by 1023.
// we are treating the mantissa as m.0 instead of 0.m
// so subtract another 52.
exponent -= 1075;
realMant = mantissa;
// normalize
while (realMant > 1.0)
{
mantissa >>= 1;
realMant /= 2;
exponent++;
}
if (neg)
{
realMant = realMant * -1;
}
result.exponent = exponent;
result.mantissa = realMant;
}
return result;
}
