examples/Delphi/ExRndU.pas

(* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is TurboPower SysTools
 *
 * The Initial Developer of the Original Code is
 * TurboPower Software
 *
 * Portions created by the Initial Developer are Copyright (C) 1996-2002
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * ***** END LICENSE BLOCK ***** *)

unit ExRndU;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms,
  Dialogs, ComCtrls, StdCtrls, ExtCtrls,
  
  StRandom;

type
  TGetRandom = function : double of object;

type
  TForm1 = class(TForm)
    imgGraph: TImage;
    cboDist: TComboBox;
    lblPrompt: TLabel;
    btnGenerate: TButton;
    prgGenProgress: TProgressBar;
    lblGraphTitle: TLabel;
    lblParms: TLabel;
    lblParm1: TLabel;
    lblParm2: TLabel;
    edtParm1: TEdit;
    edtParm2: TEdit;
    lblLeft: TLabel;
    lblRight: TLabel;
    updRight: TUpDown;
    updLeft: TUpDown;
    lblMaxY: TLabel;
    procedure btnGenerateClick(Sender: TObject);
    procedure cboDistChange(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure updRightClick(Sender: TObject; Button: TUDBtnType);
    procedure updLeftClick(Sender: TObject; Button: TUDBtnType);
    procedure FormDestroy(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    GraphLeft : double;
    GraphRight : double;
    Value1     : double;
    Value2     : double;
    PRNG : TStRandomBase;
    GetRandom : TGetRandom;

    procedure GenerateGraph(aDistInx : integer);

    procedure PrepForBeta;
    procedure PrepForCauchy;
    procedure PrepForChiSquared;
    procedure PrepForErlang;
    procedure PrepForExponential;
    procedure PrepForF;
    procedure PrepForGamma;
    procedure PrepForLogNormal;
    procedure PrepForNormal;
    procedure PrepForT;
    procedure PrepForUniform;
    procedure PrepForWeibull;

    function GetBeta : double;
    function GetCauchy : double;
    function GetChiSquared : double;
    function GetErlang : double;
    function GetExponential : double;
    function GetF : double;
    function GetGamma : double;
    function GetLogNormal : double;
    function GetNormal : double;
    function GetT : double;
    function GetUniform : double;
    function GetWeibull : double;

  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

const
  DistNames : array [0..11] of string = (
    'Beta', 'Cauchy', 'ChiSquared', 'Erlang', 'Exponential',
    'F', 'Gamma', 'LogNormal', 'Normal', 'Student''s t',
    'Uniform', 'Weibull');

const
  RandomCount = 1000000;

procedure TForm1.GenerateGraph(aDistInx : integer);
var
  Buckets : array[0..400] of integer;
  i       : integer;
  R       : double;
  Inx     : integer;
  MaxHt   : integer;
  MaxLineFactor : double;
  GraphWidth : double;
  OldPercent : integer;
  NewPercent : integer;
begin
  {zero out the buckets}
  FillChar(Buckets, sizeof(Buckets), 0);

  {calculate random numbers according to distribution, convert to a
   bucket index, and increment that bucket count}
  OldPercent := -1;
  GraphWidth := imgGraph.Width;
  for i := 1 to RandomCount do begin
    NewPercent := (i * 100) div RandomCount;
    if (NewPercent <> OldPercent) then begin
      prgGenProgress.Position := NewPercent;
      OldPercent := NewPercent;
    end;
    R := GetRandom;
    if (GraphLeft <= R) and (R <= GraphRight) then begin
      Inx := trunc((R - GraphLeft) * GraphWidth / (GraphRight - GraphLeft));
      if (0 <= Inx) and (Inx <= 400) then
        inc(Buckets[Inx]);
    end;
  end;

  {calculate the largest bucket}
  MaxHt := 1;
  for i := 0 to 400 do
    if (MaxHt < Buckets[i]) then
      MaxHt := Buckets[i];

  {draw the graph}
  imgGraph.Canvas.Lock;
  try
    imgGraph.Canvas.FillRect(Rect(0, 0, imgGraph.Width, imgGraph.Height));
    MaxLineFactor := imgGraph.Height / MaxHt;
    imgGraph.Canvas.Pen.Color := clRed;
    for i := 0 to 400 do begin
      imgGraph.Canvas.PenPos := Point(i, imgGraph.Height);
      imgGraph.Canvas.LineTo(i, imgGraph.Height - trunc(Buckets[i] * MaxLineFactor));
    end;
  finally
    imgGraph.Canvas.Unlock;
  end;

  lblMaxY.Caption := Format('Max: %8.6f', [MaxHt / RandomCount]);
end;

procedure TForm1.btnGenerateClick(Sender: TObject);
begin
  if (edtParm1.Text = '') then
    Value1 := 0.0
  else
    Value1 := StrToFloat(edtParm1.Text);
  if (edtParm2.Text = '') then
    Value2 := 0.0
  else
    Value2 := StrToFloat(edtParm2.Text);
  GenerateGraph(cboDist.ItemIndex);
end;

procedure TForm1.cboDistChange(Sender: TObject);
begin
  case cboDist.ItemIndex of
    0 : PrepForBeta;
    1 : PrepForCauchy;
    2 : PrepForChiSquared;
    3 : PrepForErlang;
    4 : PrepForExponential;
    5 : PrepForF;
    6 : PrepForGamma;
    7 : PrepForLogNormal;
    8 : PrepForNormal;
    9 : PrepForT;
    10: PrepForUniform;
    11: PrepForWeibull
  end;
  updRightClick(Self, btNext);
  updLeftClick(Self, btNext);
  edtParm1.Text := FloatToStr(Value1);
  edtParm2.Text := FloatToStr(Value2);
end;

procedure TForm1.PrepForBeta;
begin
  lblParm1.Caption := 'Shape 1:';
  lblParm1.Visible := true;
  lblParm2.Caption := 'Shape 2:';
  lblParm2.Visible := true;
  edtParm1.Visible := true;
  edtParm1.Enabled := true;
  edtParm2.Visible := true;
  edtParm2.Enabled := true;
  updLeft.Position := 0;
  updRight.Position := 1;
  Value1 := 2.0;
  Value2 := 4.0;
  GetRandom := GetBeta;
end;

procedure TForm1.PrepForCauchy;
begin
  lblParm1.Caption := '(none)';
  lblParm1.Visible := true;
  lblParm2.Visible := false;
  edtParm1.Visible := false;
  edtParm1.Enabled := false;
  edtParm2.Visible := false;
  edtParm2.Enabled := false;
  updLeft.Position := -5;
  updRight.Position := 5;
  Value1 := 0.0;
  Value2 := 0.0;
  GetRandom := GetCauchy;
end;

procedure TForm1.PrepForChiSquared;
begin
  lblParm1.Caption := 'Degrees of freedom:';
  lblParm1.Visible := true;
  lblParm2.Visible := false;
  edtParm1.Visible := true;
  edtParm1.Enabled := true;
  edtParm2.Visible := false;
  edtParm2.Enabled := false;
  updLeft.Position := 0;
  updRight.Position := 20;
  Value1 := 5.0;
  Value2 := 0.0;
  GetRandom := GetChiSquared;
end;

procedure TForm1.PrepForErlang;
begin
  lblParm1.Caption := 'Mean:';
  lblParm1.Visible := true;
  lblParm2.Caption := 'Order:';
  lblParm2.Visible := true;
  edtParm1.Visible := true;
  edtParm1.Enabled := true;
  edtParm2.Visible := true;
  edtParm2.Enabled := true;
  updLeft.Position := 0;
  updRight.Position := 5;
  Value1 := 1.0;
  Value2 := 4.0;
  GetRandom := GetErlang;
end;

procedure TForm1.PrepForExponential;
begin
  lblParm1.Caption := 'Mean:';
  lblParm1.Visible := true;
  lblParm2.Visible := false;
  edtParm1.Visible := true;
  edtParm1.Enabled := true;
  edtParm2.Visible := false;
  edtParm2.Enabled := false;
  updLeft.Position := 0;
  updRight.Position := 10;
  Value1 := 1.0;
  Value2 := 0.0;
  GetRandom := GetExponential;
end;

procedure TForm1.PrepForF;
begin
  lblParm1.Caption := 'Degrees of freedom 1:';
  lblParm1.Visible := true;
  lblParm2.Caption := 'Degrees of freedom 2:';
  lblParm2.Visible := true;
  edtParm1.Visible := true;
  edtParm1.Enabled := true;
  edtParm2.Visible := true;
  edtParm2.Enabled := true;
  updLeft.Position := 0;
  updRight.Position := 20;
  Value1 := 10.0;
  Value2 := 5.0;
  GetRandom := GetF;
end;

procedure TForm1.PrepForGamma;
begin
  lblParm1.Caption := 'Shape:';
  lblParm1.Visible := true;
  lblParm2.Caption := 'Scale:';
  lblParm2.Visible := true;
  edtParm1.Visible := true;
  edtParm1.Enabled := true;
  edtParm2.Visible := true;
  edtParm2.Enabled := true;
  updLeft.Position := 0;
  updRight.Position := 10;
  Value1 := 2.0;
  Value2 := 1.0;
  GetRandom := GetGamma;
end;

procedure TForm1.PrepForLogNormal;
begin
  lblParm1.Caption := 'Mean:';
  lblParm1.Visible := true;
  lblParm2.Caption := 'Standard deviation:';
  lblParm2.Visible := true;
  edtParm1.Visible := true;
  edtParm1.Enabled := true;
  edtParm2.Visible := true;
  edtParm2.Enabled := true;
  updLeft.Position := 0;
  updRight.Position := 10;
  Value1 := 0.0;
  Value2 := 1.0;
  GetRandom := GetLogNormal;
end;

procedure TForm1.PrepForNormal;
begin
  lblParm1.Caption := 'Mean:';
  lblParm1.Visible := true;
  lblParm2.Caption := 'Standard deviation:';
  lblParm2.Visible := true;
  edtParm1.Visible := true;
  edtParm1.Enabled := true;
  edtParm2.Visible := true;
  edtParm2.Enabled := true;
  updLeft.Position := -5;
  updRight.Position := 5;
  Value1 := 0.0;
  Value2 := 1.0;
  GetRandom := GetNormal;
end;

procedure TForm1.PrepForT;
begin
  lblParm1.Caption := 'Degrees of freedom:';
  lblParm1.Visible := true;
  lblParm2.Visible := false;
  edtParm1.Visible := true;
  edtParm1.Enabled := true;
  edtParm2.Visible := false;
  edtParm2.Enabled := false;
  updLeft.Position := -10;
  updRight.Position := 10;
  Value1 := 10.0;
  Value2 := 0.0;
  GetRandom := GetT;
end;

procedure TForm1.PrepForUniform;
begin
  lblParm1.Caption := '(none)';
  lblParm1.Visible := true;
  lblParm2.Visible := false;
  edtParm1.Visible := false;
  edtParm1.Enabled := false;
  edtParm2.Visible := false;
  edtParm2.Enabled := false;
  updLeft.Position := 0;
  updRight.Position := 1;
  Value1 := 0.0;
  Value2 := 0.0;
  GetRandom := GetUniform;
end;

procedure TForm1.PrepForWeibull;
begin
  lblParm1.Caption := 'Shape:';
  lblParm1.Visible := true;
  lblParm2.Caption := 'Scale:';
  lblParm2.Visible := true;
  edtParm1.Visible := true;
  edtParm1.Enabled := true;
  edtParm2.Visible := true;
  edtParm2.Enabled := true;
  updLeft.Position := 0;
  updRight.Position := 10;
  Value1 := 2.0;
  Value2 := 3.0;
  GetRandom := GetWeibull;
end;

function TForm1.GetBeta : double;
begin
  Result := PRNG.AsBeta(Value1, Value2)
end;

function TForm1.GetCauchy : double;
begin
  Result := PRNG.AsCauchy
end;

function TForm1.GetChiSquared : double;
begin
  if (Value1 > 65535.0) then
    raise Exception.Create(
      'TForm1.GetChiSquared: the degrees of freedom value 1 is too large for this example program');
  Result := PRNG.AsChiSquared(trunc(Value1))
end;

function TForm1.GetErlang : double;
begin
  Result := PRNG.AsErlang(Value1, trunc(Value2))
end;

function TForm1.GetExponential : double;
begin
  Result := PRNG.AsExponential(Value1)
end;

function TForm1.GetF : double;
begin
  if (Value1 > 65535.0) then
    raise Exception.Create(
      'TForm1.GetF: the degrees of freedom value 1 is too large for this example program');
  if (Value2 > 65535.0) then
    raise Exception.Create(
      'TForm1.GetF: the degrees of freedom value 2 is too large for this example program');
  Result := PRNG.AsF(trunc(Value1), trunc(Value2))
end;

function TForm1.GetGamma : double;
begin
  Result := PRNG.AsGamma(Value1, Value2)
end;

function TForm1.GetLogNormal : double;
begin
  Result := PRNG.AsLogNormal(Value1, Value2)
end;

function TForm1.GetNormal : double;
begin
  Result := PRNG.AsNormal(Value1, Value2)
end;

function TForm1.GetT : double;
begin
  if (Value1 > 65535.0) then
    raise Exception.Create(
      'TForm1.GetT: the degrees of freedom value is too large for this example program');
  Result := PRNG.AsT(trunc(Value1))
end;

function TForm1.GetUniform : double;
begin
  Result := PRNG.AsFloat
end;

function TForm1.GetWeibull : double;
begin
  Result := PRNG.AsWeibull(Value1, Value2)
end;

procedure TForm1.FormCreate(Sender: TObject);
var
  i : integer;
  UniformInx : integer;
begin
  cboDist.Items.Clear;
  UniformInx := -1;
  for i := 0 to high(DistNames) do begin
    cboDist.Items.Add(DistNames[i]);
    if (Copy(DistNames[i], 1, 7) = 'Uniform') then
      UniformInx := i;
  end;
  cboDist.ItemIndex := UniformInx;
  cboDistChange(Self);
  PRNG := TStRandomSystem.Create(0);
end;

procedure TForm1.updRightClick(Sender: TObject; Button: TUDBtnType);
begin
  lblRight.Caption := IntToStr(updRight.Position);
  GraphRight := updRight.Position;
end;

procedure TForm1.updLeftClick(Sender: TObject; Button: TUDBtnType);
begin
  lblLeft.Caption := IntToStr(updLeft.Position);
  GraphLeft := updLeft.Position;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  PRNG.Free;
end;

end.
1	torben	2671	(* *** BEGIN LICENSE BLOCK ***
2			* Version: MPL 1.1
3			*
4			* The contents of this file are subject to the Mozilla Public License Version
5			* 1.1 (the "License"); you may not use this file except in compliance with
6			* the License. You may obtain a copy of the License at
7			* http://www.mozilla.org/MPL/
8			*
9			* Software distributed under the License is distributed on an "AS IS" basis,
10			* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
11			* for the specific language governing rights and limitations under the
12			* License.
13			*
14			* The Original Code is TurboPower SysTools
15			*
16			* The Initial Developer of the Original Code is
17			* TurboPower Software
18			*
19			* Portions created by the Initial Developer are Copyright (C) 1996-2002
20			* the Initial Developer. All Rights Reserved.
21			*
22			* Contributor(s):
23			*
24			* *** END LICENSE BLOCK *** *)
25
26			unit ExRndU;
27
28			interface
29
30			uses
31			Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms,
32			Dialogs, ComCtrls, StdCtrls, ExtCtrls,
33
34			StRandom;
35
36			type
37			TGetRandom = function : double of object;
38
39			type
40			TForm1 = class(TForm)
41			imgGraph: TImage;
42			cboDist: TComboBox;
43			lblPrompt: TLabel;
44			btnGenerate: TButton;
45			prgGenProgress: TProgressBar;
46			lblGraphTitle: TLabel;
47			lblParms: TLabel;
48			lblParm1: TLabel;
49			lblParm2: TLabel;
50			edtParm1: TEdit;
51			edtParm2: TEdit;
52			lblLeft: TLabel;
53			lblRight: TLabel;
54			updRight: TUpDown;
55			updLeft: TUpDown;
56			lblMaxY: TLabel;
57			procedure btnGenerateClick(Sender: TObject);
58			procedure cboDistChange(Sender: TObject);
59			procedure FormCreate(Sender: TObject);
60			procedure updRightClick(Sender: TObject; Button: TUDBtnType);
61			procedure updLeftClick(Sender: TObject; Button: TUDBtnType);
62			procedure FormDestroy(Sender: TObject);
63			private
64			{ Private declarations }
65			public
66			{ Public declarations }
67			GraphLeft : double;
68			GraphRight : double;
69			Value1 : double;
70			Value2 : double;
71			PRNG : TStRandomBase;
72			GetRandom : TGetRandom;
73
74			procedure GenerateGraph(aDistInx : integer);
75
76			procedure PrepForBeta;
77			procedure PrepForCauchy;
78			procedure PrepForChiSquared;
79			procedure PrepForErlang;
80			procedure PrepForExponential;
81			procedure PrepForF;
82			procedure PrepForGamma;
83			procedure PrepForLogNormal;
84			procedure PrepForNormal;
85			procedure PrepForT;
86			procedure PrepForUniform;
87			procedure PrepForWeibull;
88
89			function GetBeta : double;
90			function GetCauchy : double;
91			function GetChiSquared : double;
92			function GetErlang : double;
93			function GetExponential : double;
94			function GetF : double;
95			function GetGamma : double;
96			function GetLogNormal : double;
97			function GetNormal : double;
98			function GetT : double;
99			function GetUniform : double;
100			function GetWeibull : double;
101
102			end;
103
104			var
105			Form1: TForm1;
106
107			implementation
108
109			{$R *.dfm}
110
111			const
112			DistNames : array [0..11] of string = (
113			'Beta', 'Cauchy', 'ChiSquared', 'Erlang', 'Exponential',
114			'F', 'Gamma', 'LogNormal', 'Normal', 'Student''s t',
115			'Uniform', 'Weibull');
116
117			const
118			RandomCount = 1000000;
119
120			procedure TForm1.GenerateGraph(aDistInx : integer);
121			var
122			Buckets : array[0..400] of integer;
123			i : integer;
124			R : double;
125			Inx : integer;
126			MaxHt : integer;
127			MaxLineFactor : double;
128			GraphWidth : double;
129			OldPercent : integer;
130			NewPercent : integer;
131			begin
132			{zero out the buckets}
133			FillChar(Buckets, sizeof(Buckets), 0);
134
135			{calculate random numbers according to distribution, convert to a
136			bucket index, and increment that bucket count}
137			OldPercent := -1;
138			GraphWidth := imgGraph.Width;
139			for i := 1 to RandomCount do begin
140			NewPercent := (i * 100) div RandomCount;
141			if (NewPercent <> OldPercent) then begin
142			prgGenProgress.Position := NewPercent;
143			OldPercent := NewPercent;
144			end;
145			R := GetRandom;
146			if (GraphLeft <= R) and (R <= GraphRight) then begin
147			Inx := trunc((R - GraphLeft) * GraphWidth / (GraphRight - GraphLeft));
148			if (0 <= Inx) and (Inx <= 400) then
149			inc(Buckets[Inx]);
150			end;
151			end;
152
153			{calculate the largest bucket}
154			MaxHt := 1;
155			for i := 0 to 400 do
156			if (MaxHt < Buckets[i]) then
157			MaxHt := Buckets[i];
158
159			{draw the graph}
160			imgGraph.Canvas.Lock;
161			try
162			imgGraph.Canvas.FillRect(Rect(0, 0, imgGraph.Width, imgGraph.Height));
163			MaxLineFactor := imgGraph.Height / MaxHt;
164			imgGraph.Canvas.Pen.Color := clRed;
165			for i := 0 to 400 do begin
166			imgGraph.Canvas.PenPos := Point(i, imgGraph.Height);
167			imgGraph.Canvas.LineTo(i, imgGraph.Height - trunc(Buckets[i] * MaxLineFactor));
168			end;
169			finally
170			imgGraph.Canvas.Unlock;
171			end;
172
173			lblMaxY.Caption := Format('Max: %8.6f', [MaxHt / RandomCount]);
174			end;
175
176			procedure TForm1.btnGenerateClick(Sender: TObject);
177			begin
178			if (edtParm1.Text = '') then
179			Value1 := 0.0
180			else
181			Value1 := StrToFloat(edtParm1.Text);
182			if (edtParm2.Text = '') then
183			Value2 := 0.0
184			else
185			Value2 := StrToFloat(edtParm2.Text);
186			GenerateGraph(cboDist.ItemIndex);
187			end;
188
189			procedure TForm1.cboDistChange(Sender: TObject);
190			begin
191			case cboDist.ItemIndex of
192			0 : PrepForBeta;
193			1 : PrepForCauchy;
194			2 : PrepForChiSquared;
195			3 : PrepForErlang;
196			4 : PrepForExponential;
197			5 : PrepForF;
198			6 : PrepForGamma;
199			7 : PrepForLogNormal;
200			8 : PrepForNormal;
201			9 : PrepForT;
202			10: PrepForUniform;
203			11: PrepForWeibull
204			end;
205			updRightClick(Self, btNext);
206			updLeftClick(Self, btNext);
207			edtParm1.Text := FloatToStr(Value1);
208			edtParm2.Text := FloatToStr(Value2);
209			end;
210
211			procedure TForm1.PrepForBeta;
212			begin
213			lblParm1.Caption := 'Shape 1:';
214			lblParm1.Visible := true;
215			lblParm2.Caption := 'Shape 2:';
216			lblParm2.Visible := true;
217			edtParm1.Visible := true;
218			edtParm1.Enabled := true;
219			edtParm2.Visible := true;
220			edtParm2.Enabled := true;
221			updLeft.Position := 0;
222			updRight.Position := 1;
223			Value1 := 2.0;
224			Value2 := 4.0;
225			GetRandom := GetBeta;
226			end;
227
228			procedure TForm1.PrepForCauchy;
229			begin
230			lblParm1.Caption := '(none)';
231			lblParm1.Visible := true;
232			lblParm2.Visible := false;
233			edtParm1.Visible := false;
234			edtParm1.Enabled := false;
235			edtParm2.Visible := false;
236			edtParm2.Enabled := false;
237			updLeft.Position := -5;
238			updRight.Position := 5;
239			Value1 := 0.0;
240			Value2 := 0.0;
241			GetRandom := GetCauchy;
242			end;
243
244			procedure TForm1.PrepForChiSquared;
245			begin
246			lblParm1.Caption := 'Degrees of freedom:';
247			lblParm1.Visible := true;
248			lblParm2.Visible := false;
249			edtParm1.Visible := true;
250			edtParm1.Enabled := true;
251			edtParm2.Visible := false;
252			edtParm2.Enabled := false;
253			updLeft.Position := 0;
254			updRight.Position := 20;
255			Value1 := 5.0;
256			Value2 := 0.0;
257			GetRandom := GetChiSquared;
258			end;
259
260			procedure TForm1.PrepForErlang;
261			begin
262			lblParm1.Caption := 'Mean:';
263			lblParm1.Visible := true;
264			lblParm2.Caption := 'Order:';
265			lblParm2.Visible := true;
266			edtParm1.Visible := true;
267			edtParm1.Enabled := true;
268			edtParm2.Visible := true;
269			edtParm2.Enabled := true;
270			updLeft.Position := 0;
271			updRight.Position := 5;
272			Value1 := 1.0;
273			Value2 := 4.0;
274			GetRandom := GetErlang;
275			end;
276
277			procedure TForm1.PrepForExponential;
278			begin
279			lblParm1.Caption := 'Mean:';
280			lblParm1.Visible := true;
281			lblParm2.Visible := false;
282			edtParm1.Visible := true;
283			edtParm1.Enabled := true;
284			edtParm2.Visible := false;
285			edtParm2.Enabled := false;
286			updLeft.Position := 0;
287			updRight.Position := 10;
288			Value1 := 1.0;
289			Value2 := 0.0;
290			GetRandom := GetExponential;
291			end;
292
293			procedure TForm1.PrepForF;
294			begin
295			lblParm1.Caption := 'Degrees of freedom 1:';
296			lblParm1.Visible := true;
297			lblParm2.Caption := 'Degrees of freedom 2:';
298			lblParm2.Visible := true;
299			edtParm1.Visible := true;
300			edtParm1.Enabled := true;
301			edtParm2.Visible := true;
302			edtParm2.Enabled := true;
303			updLeft.Position := 0;
304			updRight.Position := 20;
305			Value1 := 10.0;
306			Value2 := 5.0;
307			GetRandom := GetF;
308			end;
309
310			procedure TForm1.PrepForGamma;
311			begin
312			lblParm1.Caption := 'Shape:';
313			lblParm1.Visible := true;
314			lblParm2.Caption := 'Scale:';
315			lblParm2.Visible := true;
316			edtParm1.Visible := true;
317			edtParm1.Enabled := true;
318			edtParm2.Visible := true;
319			edtParm2.Enabled := true;
320			updLeft.Position := 0;
321			updRight.Position := 10;
322			Value1 := 2.0;
323			Value2 := 1.0;
324			GetRandom := GetGamma;
325			end;
326
327			procedure TForm1.PrepForLogNormal;
328			begin
329			lblParm1.Caption := 'Mean:';
330			lblParm1.Visible := true;
331			lblParm2.Caption := 'Standard deviation:';
332			lblParm2.Visible := true;
333			edtParm1.Visible := true;
334			edtParm1.Enabled := true;
335			edtParm2.Visible := true;
336			edtParm2.Enabled := true;
337			updLeft.Position := 0;
338			updRight.Position := 10;
339			Value1 := 0.0;
340			Value2 := 1.0;
341			GetRandom := GetLogNormal;
342			end;
343
344			procedure TForm1.PrepForNormal;
345			begin
346			lblParm1.Caption := 'Mean:';
347			lblParm1.Visible := true;
348			lblParm2.Caption := 'Standard deviation:';
349			lblParm2.Visible := true;
350			edtParm1.Visible := true;
351			edtParm1.Enabled := true;
352			edtParm2.Visible := true;
353			edtParm2.Enabled := true;
354			updLeft.Position := -5;
355			updRight.Position := 5;
356			Value1 := 0.0;
357			Value2 := 1.0;
358			GetRandom := GetNormal;
359			end;
360
361			procedure TForm1.PrepForT;
362			begin
363			lblParm1.Caption := 'Degrees of freedom:';
364			lblParm1.Visible := true;
365			lblParm2.Visible := false;
366			edtParm1.Visible := true;
367			edtParm1.Enabled := true;
368			edtParm2.Visible := false;
369			edtParm2.Enabled := false;
370			updLeft.Position := -10;
371			updRight.Position := 10;
372			Value1 := 10.0;
373			Value2 := 0.0;
374			GetRandom := GetT;
375			end;
376
377			procedure TForm1.PrepForUniform;
378			begin
379			lblParm1.Caption := '(none)';
380			lblParm1.Visible := true;
381			lblParm2.Visible := false;
382			edtParm1.Visible := false;
383			edtParm1.Enabled := false;
384			edtParm2.Visible := false;
385			edtParm2.Enabled := false;
386			updLeft.Position := 0;
387			updRight.Position := 1;
388			Value1 := 0.0;
389			Value2 := 0.0;
390			GetRandom := GetUniform;
391			end;
392
393			procedure TForm1.PrepForWeibull;
394			begin
395			lblParm1.Caption := 'Shape:';
396			lblParm1.Visible := true;
397			lblParm2.Caption := 'Scale:';
398			lblParm2.Visible := true;
399			edtParm1.Visible := true;
400			edtParm1.Enabled := true;
401			edtParm2.Visible := true;
402			edtParm2.Enabled := true;
403			updLeft.Position := 0;
404			updRight.Position := 10;
405			Value1 := 2.0;
406			Value2 := 3.0;
407			GetRandom := GetWeibull;
408			end;
409
410			function TForm1.GetBeta : double;
411			begin
412			Result := PRNG.AsBeta(Value1, Value2)
413			end;
414
415			function TForm1.GetCauchy : double;
416			begin
417			Result := PRNG.AsCauchy
418			end;
419
420			function TForm1.GetChiSquared : double;
421			begin
422			if (Value1 > 65535.0) then
423			raise Exception.Create(
424			'TForm1.GetChiSquared: the degrees of freedom value 1 is too large for this example program');
425			Result := PRNG.AsChiSquared(trunc(Value1))
426			end;
427
428			function TForm1.GetErlang : double;
429			begin
430			Result := PRNG.AsErlang(Value1, trunc(Value2))
431			end;
432
433			function TForm1.GetExponential : double;
434			begin
435			Result := PRNG.AsExponential(Value1)
436			end;
437
438			function TForm1.GetF : double;
439			begin
440			if (Value1 > 65535.0) then
441			raise Exception.Create(
442			'TForm1.GetF: the degrees of freedom value 1 is too large for this example program');
443			if (Value2 > 65535.0) then
444			raise Exception.Create(
445			'TForm1.GetF: the degrees of freedom value 2 is too large for this example program');
446			Result := PRNG.AsF(trunc(Value1), trunc(Value2))
447			end;
448
449			function TForm1.GetGamma : double;
450			begin
451			Result := PRNG.AsGamma(Value1, Value2)
452			end;
453
454			function TForm1.GetLogNormal : double;
455			begin
456			Result := PRNG.AsLogNormal(Value1, Value2)
457			end;
458
459			function TForm1.GetNormal : double;
460			begin
461			Result := PRNG.AsNormal(Value1, Value2)
462			end;
463
464			function TForm1.GetT : double;
465			begin
466			if (Value1 > 65535.0) then
467			raise Exception.Create(
468			'TForm1.GetT: the degrees of freedom value is too large for this example program');
469			Result := PRNG.AsT(trunc(Value1))
470			end;
471
472			function TForm1.GetUniform : double;
473			begin
474			Result := PRNG.AsFloat
475			end;
476
477			function TForm1.GetWeibull : double;
478			begin
479			Result := PRNG.AsWeibull(Value1, Value2)
480			end;
481
482			procedure TForm1.FormCreate(Sender: TObject);
483			var
484			i : integer;
485			UniformInx : integer;
486			begin
487			cboDist.Items.Clear;
488			UniformInx := -1;
489			for i := 0 to high(DistNames) do begin
490			cboDist.Items.Add(DistNames[i]);
491			if (Copy(DistNames[i], 1, 7) = 'Uniform') then
492			UniformInx := i;
493			end;
494			cboDist.ItemIndex := UniformInx;
495			cboDistChange(Self);
496			PRNG := TStRandomSystem.Create(0);
497			end;
498
499			procedure TForm1.updRightClick(Sender: TObject; Button: TUDBtnType);
500			begin
501			lblRight.Caption := IntToStr(updRight.Position);
502			GraphRight := updRight.Position;
503			end;
504
505			procedure TForm1.updLeftClick(Sender: TObject; Button: TUDBtnType);
506			begin
507			lblLeft.Caption := IntToStr(updLeft.Position);
508			GraphLeft := updLeft.Position;
509			end;
510
511			procedure TForm1.FormDestroy(Sender: TObject);
512			begin
513			PRNG.Free;
514			end;
515
516			end.