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	(* *** 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.