A WeightedHarmonicMean functions to Maths category

Added Double, Cardinal and Integer overloads of the functions.

Added source code file for each function.

Updated maths.ini with meta data for each function.

Author: delphidabbler

collection/687.dat

@@ -0,0 +1,19 @@
+function WeightedHarmonicMean(const Values: array of Double;
+  const Weights: array of Double): Double; overload;
+var
+  Sum: Double;
+  Idx: Integer;
+  NormalisedWeights: Types.TDoubleDynArray;
+begin
+  if System.Length(Values) = 0 then
+    raise SysUtils.EArgumentException.Create('Array of values is empty');
+  if System.Length(Values) <> System.Length(Weights) then
+    raise SysUtils.EArgumentException.Create(
+      'Number of values and number of weights must be the same'
+    );
+  NormalisedWeights := NormaliseByWeight(Weights);
+  Sum := 0.0;
+  for Idx := 0 to Pred(System.Length(Values)) do
+    Sum := Sum + NormalisedWeights[Idx] / Values[Idx];
+  Result := 1.0 / Sum;
+end;

collection/688.dat

@@ -0,0 +1,11 @@
+function WeightedHarmonicMean(const Values: array of Cardinal;
+  const Weights: array of Double): Double; overload;
+var
+  Idx: Integer;
+  FloatValues: Types.TDoubleDynArray;
+begin
+  System.Setlength(FloatValues, System.Length(Values));
+  for Idx := 0 to Pred(System.Length(Values)) do
+    FloatValues[Idx] := Values[Idx];
+  Result := WeightedHarmonicMean(FloatValues, Weights);
+end;

collection/689.dat

@@ -0,0 +1,11 @@
+function WeightedHarmonicMean(const Values: array of Integer;
+  const Weights: array of Double): Double; overload;
+var
+  Idx: Integer;
+  FloatValues: Types.TDoubleDynArray;
+begin
+  System.Setlength(FloatValues, System.Length(Values));
+  for Idx := 0 to Pred(System.Length(Values)) do
+    FloatValues[Idx] := Values[Idx];
+  Result := WeightedHarmonicMean(FloatValues, Weights);
+end;

collection/maths.ini

@@ -2166,3 +2166,48 @@ AdvancedTest.URL="https://github.com/delphidabbler/code-snippets/tree/master/tes
 Snip=686.dat
 DelphiXE=Y
 Delphi12A=Y
+
+[WeightedHarmonicMean_Double]
+DisplayName="WeightedHarmonicMean (Double overload)"
+DescEx="<p>Calculates and returns the weighted harmonic mean of the array <var>Values</var> of positive <var>Double</var> values where each element is weighted by the corresponding element in the array <var>Weights</var>.</p><p>An <var>EArgumentException</var> exception is raised if any of the following pre-conditions are not met: <var>Values</var> must be non-empty; all elements of <var>Values</var> must be positive; <var>Values</var> &amp; <var>Weights</var> must have the same number of elements; all elements of <var>Weights</var> must be non-negative, with at least one element being non-zero.</p>"
+Extra="<p>See <a href="https://en.wikipedia.org/wiki/Harmonic_mean#Weighted_harmonic_mean">Wikipedia</a> for information about the weighted harmonic mean.</p>"
+Kind=routine
+Units=SysUtils,Types
+Depends=NormaliseByWeight_Double
+SeeAlso=HarmonicMean_Double,WeightedHarmonicMean_Cardinal,WeightedHarmonicMean_Integer,WeightedArithMean_Double,WeightedGeoMean_Double
+TestInfo=advanced
+AdvancedTest.Level=unit-tests
+AdvancedTest.URL="https://github.com/delphidabbler/code-snippets/tree/master/tests/Cat-Maths"
+Snip=687.dat
+DelphiXE=Y
+Delphi12A=Y
+
+[WeightedHarmonicMean_Cardinal]
+DisplayName="WeightedHarmonicMean (Cardinal overload)"
+DescEx="<p>Calculates and returns the weighted harmonic mean of the array <var>Values</var> of positive <var>Cardinal</var> values where each element is weighted by the corresponding element in the array <var>Weights</var>.</p><p>An <var>EArgumentException</var> exception is raised if any of the following pre-conditions are not met: <var>Values</var> must be non-empty; all elements of <var>Values</var> must be positive; <var>Values</var> &amp; <var>Weights</var> must have the same number of elements; all elements of <var>Weights</var> must be non-negative, with at least one element being non-zero.</p>"
+Extra="<p>See <a href="https://en.wikipedia.org/wiki/Harmonic_mean#Weighted_harmonic_mean">Wikipedia</a> for information about the weighted harmonic mean.</p>"
+Kind=routine
+Units=Types
+Depends=WeightedHarmonicMean_Double
+SeeAlso=HarmonicMean_Cardinal,WeightedHarmonicMean_Double,WeightedHarmonicMean_Integer,WeightedArithMean_Cardinal,WeightedGeoMean_Cardinal
+TestInfo=advanced
+AdvancedTest.Level=unit-tests
+AdvancedTest.URL="https://github.com/delphidabbler/code-snippets/tree/master/tests/Cat-Maths"
+Snip=688.dat
+DelphiXE=Y
+Delphi12A=Y
+
+[WeightedHarmonicMean_Integer]
+DisplayName="WeightedHarmonicMean (Integer overload)"
+DescEx="<p>Calculates and returns the weighted harmonic mean of the array <var>Values</var> of positive <var>Integer</var> values where each element is weighted by the corresponding element in the array <var>Weights</var>.</p><p>An <var>EArgumentException</var> exception is raised if any of the following pre-conditions are not met: <var>Values</var> must be non-empty; all elements of <var>Values</var> must be positive; <var>Values</var> &amp; <var>Weights</var> must have the same number of elements; all elements of <var>Weights</var> must be non-negative, with at least one element being non-zero.</p>"
+Extra="<p>See <a href="https://en.wikipedia.org/wiki/Harmonic_mean#Weighted_harmonic_mean">Wikipedia</a> for information about the weighted harmonic mean.</p>"
+Kind=routine
+Units=Types
+Depends=WeightedHarmonicMean_Double
+SeeAlso=HarmonicMean_Integer,WeightedHarmonicMean_Double,WeightedHarmonicMean_Cardinal,WeightedArithMean_Integer,WeightedGeoMean_Integer
+TestInfo=advanced
+AdvancedTest.Level=unit-tests
+AdvancedTest.URL="https://github.com/delphidabbler/code-snippets/tree/master/tests/Cat-Maths"
+Snip=689.dat
+DelphiXE=Y
+Delphi12A=Y