/// <summary>
/// Rounds to decimal places.
/// </summary>
/// <seealso cref="Numbers.RoundToDecimalPlaces">https://en.wikipedia.org/wiki/Significant_figures</seealso>
/// <param name="value">The value.</param>
/// <param name="decimalPlaces">The number of decimal places.</param>
/// <param name="roundingTieBreaker">Method by which rounding is performed if the triggering rounding number is 5.</param>
/// <returns>System.Double.</returns>
public static string DisplayRoundedToDecimalPlaces(
this double value,
int decimalPlaces,
RoundingTieBreaker roundingTieBreaker = RoundingTieBreaker.HalfAwayFromZero)
{
return(Numbers.DisplayRoundedToDecimalPlaces(value, decimalPlaces, roundingTieBreaker));
}
/// <summary>
/// Rounds to decimal places.
/// </summary>
/// <seealso cref="RoundToDecimalPlaces">https://en.wikipedia.org/wiki/Significant_figures</seealso>
/// <param name="value">The value.</param>
/// <param name="decimalPlaces">The number of decimal places.</param>
/// <param name="roundingTieBreaker">Method by which rounding is performed if the triggering rounding number is 5.</param>
/// <returns>System.Double.</returns>
public static double RoundToDecimalPlaces(
double value,
int decimalPlaces,
RoundingTieBreaker roundingTieBreaker = RoundingTieBreaker.HalfAwayFromZero)
{
return(NMath.Round(value, decimalPlaces, midpointRounding(roundingTieBreaker)));
}
/// <summary>
/// Rounds to significant figures.
/// </summary>
/// <seealso cref="Numbers.RoundToSignificantFigures">https://en.wikipedia.org/wiki/Significant_figures</seealso>
/// <param name="value">The value.</param>
/// <param name="significantFigures">The number of significant figures.</param>
/// <param name="roundingTieBreaker">Method by which rounding is performed if the triggering rounding number is 5.</param>
/// <returns>System.Double.</returns>
public static string DisplayRoundedToSignificantFigures(
this double value,
int significantFigures,
RoundingTieBreaker roundingTieBreaker = RoundingTieBreaker.HalfAwayFromZero)
{
return(Numbers.DisplayRoundedToSignificantFigures(value, significantFigures, roundingTieBreaker));
}
/// <summary>
/// Rounds to decimal places.
/// </summary>
/// <seealso cref="RoundToDecimalPlaces">https://en.wikipedia.org/wiki/Significant_figures</seealso>
/// <param name="value">The value.</param>
/// <param name="decimalPlaces">The number of decimal places.</param>
/// <param name="roundingTieBreaker">Method by which rounding is performed if the triggering rounding number is 5.</param>
/// <returns>System.Double.</returns>
public static string DisplayRoundedToDecimalPlaces(
double value,
int decimalPlaces,
RoundingTieBreaker roundingTieBreaker = RoundingTieBreaker.HalfAwayFromZero)
{
value = RoundToDecimalPlaces(value, decimalPlaces, roundingTieBreaker);
string valueAsString = value.ToString(CultureInfo.InvariantCulture);
if (decimalPlaces <= 0)
{
return(valueAsString);
}
// Get number of decimal places
int prePaddingLength = valueAsString.Length;
string wholeNumber;
string decimalNumber = "";
int valueDecimalLength = valueAsString.Length;
if (valueAsString.Contains(CultureInfo.InvariantCulture.NumberFormat.NumberDecimalSeparator))
{
wholeNumber = valueAsString.Split(CultureInfo.InvariantCulture.NumberFormat.NumberDecimalSeparator)[0];
decimalNumber = valueAsString.Split(CultureInfo.InvariantCulture.NumberFormat.NumberDecimalSeparator)[1];
valueDecimalLength -= (wholeNumber.Length + 1);
}
else
{
wholeNumber = valueAsString;
valueDecimalLength = 0;
if (wholeNumber[0] == '0')
{
prePaddingLength += 1;
}
}
string result = wholeNumber + CultureInfo.InvariantCulture.NumberFormat.NumberDecimalSeparator + decimalNumber;
int zeroPadding = decimalPlaces - valueDecimalLength;
result = result.PadRight(prePaddingLength + zeroPadding, '0');
return(result);
}
/// <summary>
/// Rounds to significant figures.
/// </summary>
/// <seealso cref="RoundToSignificantFigures">https://en.wikipedia.org/wiki/Significant_figures</seealso>
/// <param name="value">The value.</param>
/// <param name="significantFigures">The number of significant figures.</param>
/// <param name="roundingTieBreaker">Method by which rounding is performed if the triggering rounding number is 5.</param>
/// <returns>System.Double.</returns>
public static double RoundToSignificantFigures(
double value,
int significantFigures,
RoundingTieBreaker roundingTieBreaker = RoundingTieBreaker.HalfAwayFromZero)
{
if (value == 0 || significantFigures == 0)
{
return(0);
}
// Get value scaled to having sig figs result as an integer e.g. 4th sig fig 12345 = 1234.5 or 0.00012345 = 1234.5, 7th sig fig 12.345 = 1234500
double scale = NMath.Pow(10, NMath.Floor(NMath.Log10(NMath.Abs(value))) + 1 - significantFigures);
double valueScale = value / scale;
// Round in case floating point affects number outside of precision (e.g. for 0.545 vs. 0.5449999999 for rounding to 0.6)
double valueScaleRounded = NMath.Round(valueScale, 2);
// scale back up
return(scale * NMath.Round(valueScaleRounded, midpointRounding(roundingTieBreaker)));
}
/// <summary>
/// Rounds to significant figures.
/// </summary>
/// <seealso cref="Numbers.RoundToSignificantFigures">https://en.wikipedia.org/wiki/Significant_figures</seealso>
/// <param name="value">The value.</param>
/// <param name="significantFigures">The number of significant figures.</param>
/// <param name="roundingTieBreaker">Method by which rounding is performed if the triggering rounding number is 5.</param>
/// <returns>System.Double.</returns>
public static double RoundToSignificantFigures(this int value, int significantFigures, RoundingTieBreaker roundingTieBreaker = RoundingTieBreaker.HalfAwayFromZero)
{
return(Numbers.RoundToSignificantFigures(value, significantFigures, roundingTieBreaker));
}
/// <summary>
/// Rounds to significant figures.
/// </summary>
/// <seealso cref="RoundToSignificantFigures">https://en.wikipedia.org/wiki/Significant_figures</seealso>
/// <param name="value">The value.</param>
/// <param name="significantFigures">The number of significant figures.</param>
/// <param name="roundingTieBreaker">Method by which rounding is performed if the triggering rounding number is 5.</param>
/// <returns>System.Double.</returns>
public static string DisplayRoundedToSignificantFigures(
double value,
int significantFigures,
RoundingTieBreaker roundingTieBreaker = RoundingTieBreaker.HalfAwayFromZero)
{
value = RoundToSignificantFigures(value, significantFigures, roundingTieBreaker);
string valueAsString = value.ToString(CultureInfo.InvariantCulture);
if (significantFigures <= 0)
{
return(valueAsString);
}
// Get number of decimal places
int prePaddingLength = valueAsString.Length;
string wholeNumber;
string decimalNumber = "";
int wholeNumberLength;
if (valueAsString.Contains(CultureInfo.InvariantCulture.NumberFormat.NumberDecimalSeparator))
{
wholeNumber = valueAsString.Split(CultureInfo.InvariantCulture.NumberFormat.NumberDecimalSeparator)[0];
decimalNumber = valueAsString.Split(CultureInfo.InvariantCulture.NumberFormat.NumberDecimalSeparator)[1];
wholeNumberLength = (wholeNumber[0] == '-') ? wholeNumber.Length - 1 : wholeNumber.Length;
}
else
{
wholeNumber = valueAsString;
wholeNumberLength = (wholeNumber[0] == '-') ? wholeNumber.Length - 1 : wholeNumber.Length;
if (wholeNumber[0] == '0')
{
prePaddingLength += 1;
}
else if (significantFigures <= wholeNumberLength)
{
return(valueAsString);
}
}
int valueSigFigLength;
char firstInteger = (wholeNumber[0] == '-') ? wholeNumber[1] : wholeNumber[0];
if (valueAsString.Contains(CultureInfo.InvariantCulture.NumberFormat.NumberDecimalSeparator) && firstInteger != '0')
{
valueSigFigLength = (wholeNumber[0] == '-') ? valueAsString.Length - 2 : valueAsString.Length - 1;
}
else
{
string sigFigAsString = valueAsString.TrimStart('-')
.TrimStart('0')
.Replace(CultureInfo.InvariantCulture.NumberFormat.NumberDecimalSeparator, "")
.TrimStart('0');
valueSigFigLength = sigFigAsString.Length;
}
string separator = ((significantFigures >= wholeNumberLength) || firstInteger == '0') ? CultureInfo.InvariantCulture.NumberFormat.NumberDecimalSeparator : "";
string result = wholeNumber + separator + decimalNumber;
int zeroPadding = significantFigures - valueSigFigLength;
result = result.PadRight(prePaddingLength + zeroPadding, '0');
return(result);
}
/// <summary>
/// Returns System.Math enum for the corresponding midpoint rounding method.
/// </summary>
/// <param name="roundingTieBreaker">The rounding tie breaker.</param>
/// <returns>MidpointRounding.</returns>
private static MidpointRounding midpointRounding(RoundingTieBreaker roundingTieBreaker)
{
return((roundingTieBreaker == RoundingTieBreaker.HalfAwayFromZero) ? MidpointRounding.AwayFromZero : MidpointRounding.ToEven);
}
