unit GroupFreqUnit;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs,
  StdCtrls, Buttons, ExtCtrls, MainUnit, OutPutUnit, FunctionsLib, GraphLib,
  Globals, DataProcs;

type

  { TGroupFreqForm }

  TGroupFreqForm = class(TForm)
    GrpInBtn: TBitBtn;
    GrpOutBtn: TBitBtn;
    CancelBtn: TButton;
    ComputeBtn: TButton;
    GrpVarEdit: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    Memo1: TMemo;
    OptionsBox: TRadioGroup;
    ResetBtn: TButton;
    ReturnBtn: TButton;
    VarList: TListBox;
    procedure ComputeBtnClick(Sender: TObject);
    procedure GrpInBtnClick(Sender: TObject);
    procedure GrpOutBtnClick(Sender: TObject);
    procedure ResetBtnClick(Sender: TObject);
  private
    { private declarations }
  public
    { public declarations }
  end; 

var
  GroupFreqForm: TGroupFreqForm;

implementation

{ TGroupFreqForm }

procedure TGroupFreqForm.ResetBtnClick(Sender: TObject);
VAR i : integer;
begin
     VarList.Clear;
     for i := 1 to NoVariables do
         VarList.Items.Add(OS3MainFrm.DataGrid.Cells[i,0]);
     GrpVarEdit.Text := '';
     GrpInBtn.Visible := true;
     GrpOutBtn.Visible := false;
end;

procedure TGroupFreqForm.GrpInBtnClick(Sender: TObject);
VAR index : integer;
begin
     index := VarList.ItemIndex;
     if index < 0 then exit;
     GrpVarEdit.Text := VarList.Items.Strings[index];
     VarList.Items.Delete(index);
     GrpInBtn.Visible := false;
     GrpOutBtn.Visible := true;
end;

procedure TGroupFreqForm.ComputeBtnClick(Sender: TObject);
VAR
  nogroups, mingrp, maxgrp, grpcol, tempcol, value, minfreq, maxfreq : integer;
  labelstr : string;
  results, prompt : boolean;
  result, intvalue, i, j : integer;
  dblvalue : double;
  strvalue : string;
  freq : IntDyneVec;
  plottype : integer;
begin
     // get the variable to analyze

  grpcol := 0;
  for i := 1 to NoVariables do
      begin
        strvalue := Trim(OS3MainFrm.DataGrid.Cells[i,0]);
        if GrpVarEdit.Text = strvalue then grpcol := i;
      end;
  labelstr := GrpVarEdit.Text;
  mingrp := 1000;
  maxgrp := -1000;
  for i := 1 to NoCases do
      begin
        if not ValidValue(i,grpcol) then continue;
        value := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[grpcol,i])));
        if value < mingrp then mingrp := value;
        if value > maxgrp then maxgrp := value;
      end;
  nogroups := maxgrp - mingrp + 1;
  if nogroups < 2 then
  begin
    ShowMessage('One or fewer groups found.  Returning.');
    exit;
  end;
  // setup frequency array and count cases in each group
  SetLength(freq,NoGroups+1);
  for i := 0 to NoGroups do freq[i] := 0;
  for i := 1 to NoCases do
      begin
        if not ValidValue(i,grpcol) then continue;
        value := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[grpcol,i])));
         value := value - mingrp;
         freq[value] := freq[value] + 1;
      end;
  // get min and max frequencies and check for existence of a range
  minfreq := 10000;
  maxfreq := -10000;
  for i := 0 to NoGroups-1 do
      begin
        if freq[i] < minfreq then minfreq := freq[i];
        if freq[i] > maxfreq then maxfreq := freq[i];
      end;
  if minfreq = maxfreq then
  begin
    ShowMessage('All groups have equal frequencies.  Cannot plot.');
    freq := nil;
    exit;
  end;
  plottype := OptionsBox.ItemIndex + 1;
  if plottype = 3 then plottype := 1
  else if plottype = 4 then plottype := 2
  else if plottype = 1 then plottype := 9
  else if plottype = 2 then plottype := 10;

  // plot the frequencies
  SetLength(GraphFrm.Xpoints,1,nogroups+1);
  SetLength(GraphFrm.Ypoints,1,nogroups+1);
  GraphFrm.nosets := 1;
  GraphFrm.nbars := nogroups;
  GraphFrm.Heading := 'Frequency Distribution';
  GraphFrm.XTitle := 'Values of ' + labelstr;
  GraphFrm.YTitle := 'Frequency';
  GraphFrm.barwideprop := 0.5;
  GraphFrm.AutoScale := false;
  GraphFrm.miny := 0.0;
  GraphFrm.maxy := maxfreq;
  GraphFrm.GraphType := plottype;
  GraphFrm.BackColor := clYellow;
  GraphFrm.WallColor := clBlack;
  GraphFrm.FloorColor := clLtGray;
  GraphFrm.ShowBackWall := true;
  for i := 0 to nogroups do
      begin
        GraphFrm.Ypoints[0,i] := freq[i];
        GraphFrm.Xpoints[0,i] := mingrp + i;
      end;
  GraphFrm.ShowModal;
  GraphFrm.Xpoints := nil;
  GraphFrm.Ypoints := nil;
end;

procedure TGroupFreqForm.GrpOutBtnClick(Sender: TObject);
begin
  if GrpVarEdit.Text = '' then exit;
  VarList.Items.Add(GrpVarEdit.Text);
  GrpVarEdit.Text := '';
  GrpInBtn.Visible := true;
  GrpOutBtn.Visible := false;
end;

initialization
  {$I groupfrequnit.lrs}

end.