Overload List
| # | Signature | Description |
|---|---|---|
| 1 | function Percentile(const X: TVec; P: Double; Method: TPercentileMethod): Double; | Percentile. |
| 2 | procedure Percentile(const X: TVec; const P: TDoubleArray; var Percentiles: TDoubleArray; Method: TPercentileMethod); | Percentile (several percentiles in one go). |
Overload 1: function Percentile(const X: TVec; P: Double; Method: TPercentileMethod): Double;
Percentile.
| # | Name | Description |
|---|---|---|
| 1 | X | Data. An exception is raised if X is complex. |
| 2 | P | Defines the 100*p percentile. The parameter P must lie in the interval (0,1), otherwise an exception is raised. |
| 3 | Method | Defines one of the available methods for calculating percentile. Software packages use different methods to calculate percentiles. For example, Excel uses pctMethodNMinus, while on the other hand, NCSS's default method is pctMethodNPlus. |
Returns: Double - the 100*P th percentile of all X vector elements. The 100*P -th percentile is defined as the value that is greater than 100*P percent of the values in X.
Examples
Uses MtxExpr, Math387, Statistics;
procedure Example;
var a: Vector;
PrcRes: double;
begin
a.SetIt(false,[1, 2, 3, 10, 15, 21]);
PrcRes := Percentile(a,0.75); // PrcRes = 16.5
PrcRes := Percentile(a,0.75, pctMethodNMinus); // PrcRes = 13.75
PrcRes := Percentile(a,0.75,pctMethodClosestN); // PrcRes = 10
end;See Also: Statistics.InterQuartile
Overload 2: procedure Percentile(const X: TVec; const P: TDoubleArray; var Percentiles: TDoubleArray; Method: TPercentileMethod);
Percentile (several percentiles in one go).
| # | Name | Type | Description |
|---|---|---|---|
| 1 | X | TVec | |
| 2 | P | TDoubleArray | |
| 3 | Percentiles | TDoubleArray | |
| 4 | Method | TPercentileMethod |
Result: stored in self (calling object)
Remarks:
This overload calculates percentiles for all P elements in one pass. The advantage of this overload is X sample values only have to be sorted once.
Examples
procedure Example;
var Data: Vector;
P, Pct: Array of double;
begin
Data.LoadFromFile('c:\temp\Examples\Data\Percentile.vec');
SetLength(P,4);
SetLength(Pct,4);
Percentile(Data,P,Pct);
end;