/// <summary>
/// Finds the base-10 logarithm of a number.
/// </summary>
/// <param name="number">Number greater than 0.</param>
/// <returns name="log">Logarithm of the number.</returns>
/// <search>logarithm</search>
public static double Log10(double number)
{
return(CSMath.Log10(number));
}
// Return the new type char to use
// opts.Precision will be set to the nubmer of digits to display after the decimal point
private char AdjustForG(char type, double v)
{
if (type != 'G' && type != 'g')
{
return(type);
}
if (Double.IsNaN(v) || Double.IsInfinity(v))
{
return(type);
}
double absV = SM.Abs(v);
if ((v != 0.0) && // 0.0 should not be displayed as scientific notation
absV < 1e-4 || // Values less than 0.0001 will need scientific notation
absV >= SM.Pow(10, _opts.Precision)) // Values bigger than 1e<precision> will need scientific notation
// One digit is displayed before the decimal point. Hence, we need one fewer than the precision after the decimal point
{
int fractionDigitsRequired = (_opts.Precision - 1);
string expForm = absV.ToString("E" + fractionDigitsRequired);
string mantissa = expForm.Substring(0, expForm.IndexOf('E')).TrimEnd(zero);
// We do -2 to ignore the digit before the decimal point and the decimal point itself
Debug.Assert(mantissa[1] == '.');
_opts.Precision = mantissa.Length - 2;
type = (type == 'G') ? 'E' : 'e';
}
else
{
// "0.000ddddd" is allowed when the precision is 5. The 3 leading zeros are not counted
int numberDecimalDigits = _opts.Precision;
if (absV < 1e-3)
{
numberDecimalDigits += 3;
}
else if (absV < 1e-2)
{
numberDecimalDigits += 2;
}
else if (absV < 1e-1)
{
numberDecimalDigits += 1;
}
string fixedPointForm = absV.ToString("F" + numberDecimalDigits, CultureInfo.InvariantCulture).TrimEnd(zero);
string fraction = fixedPointForm.Substring(fixedPointForm.IndexOf('.') + 1);
if (absV < 1.0)
{
_opts.Precision = fraction.Length;
}
else
{
int digitsBeforeDecimalPoint = 1 + (int)SM.Log10(absV);
_opts.Precision = SM.Min(_opts.Precision - digitsBeforeDecimalPoint, fraction.Length);
}
type = 'f';
}
return(type);
}
public static double Log10(double value)
{
return(CSMath.Log10(value));
}
public static double Log10(double d) => Math.Log10(d);
public static double Log10(double d)
{
return(Math.Log10(d));
}
static double IFloatingPoint <double> .Log10(double x) => Math.Log10(x);
/// <summary> /// Represents the log base ten of e. /// </summary> /// <returns>System.Double.</returns> public static double Log10E() => NMath.Log10(NMath.E);