unit ProbChiSqrUnit;

{$mode objfpc}{$H+}
{$WARN 6058 off : Call to subroutine "$1" marked as inline is not inlined}
interface

uses
  Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs,
  StdCtrls, ExtCtrls,
  FunctionsLib;

type

  { TChiSqrProbForm }

  TChiSqrProbForm = class(TForm)
    Bevel1: TBevel;
    CancelBtn: TButton;
    ChiSqrEdit: TEdit;
    ComputeBtn: TButton;
    DFEdit: TEdit;
    Panel1: TPanel;
    ProbEdit: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    ResetBtn: TButton;
    ReturnBtn: TButton;
    procedure ComputeBtnClick(Sender: TObject);
    procedure FormActivate(Sender: TObject);
    procedure ResetBtnClick(Sender: TObject);
  private
    { private declarations }
  public
    { public declarations }
  end; 

var
  ChiSqrProbForm: TChiSqrProbForm;

implementation

{$R *.lfm}

uses
  Math, MathUnit, Utils;

{ TChiSqrProbForm }

procedure TChiSqrProbForm.ResetBtnClick(Sender: TObject);
begin
  ChiSqrEdit.Text := '';
  DFEdit.Text := '';
  ProbEdit.Text := '';
end;

procedure TChiSqrProbForm.ComputeBtnClick(Sender: TObject);
var
  chiSqr, prob: double;
  DF: integer;
begin
  if not MyTryStrToFloat(ChiSqrEdit.Text, chiSqr) then
  begin
    ChiSqrEdit.SetFocus;
    ErrorMsg('No valid number.');
    exit;
  end;

  if not TryStrToInt(DFEdit.Text, DF) or (DF <= 0) then begin
    DFEdit.SetFocus;
    ErrorMsg('No a valid integer (must be positive).');
    exit;
  end;

  prob := 1.0 - ChiSquaredProb(ChiSqr, DF);
  ProbEdit.Text := Format('%6.4f', [prob]);
end;

procedure TChiSqrProbForm.FormActivate(Sender: TObject);
var
  w: Integer;
begin
  w := MaxValue([CancelBtn.Width, ResetBtn.Width, ComputeBtn.Width, ReturnBtn.Width]);
  CancelBtn.Constraints.MinWidth := w;
  ResetBtn.Constraints.MinWidth := w;
  ComputeBtn.Constraints.MinWidth := w;
  ReturnBtn.Constraints.MinWidth := w;
end;

end.