PROGRAM DemoScript_FunctionPlotter;

//////////////////////////////////////////////////////////////////////
//  #sign: Max: MAXBOX10: 11/04/2016 23:21:13 
//  Purpose: Grabs script to getScriptAndRun procedure              //
//  #path>ples\C:\maXbox\maxbox3\maxbox3\maXbox3\examples\          //
//  Lines of Code #locs:194
//////////////////////////////////////////////////////////////////////

Const 
 DIM = 790;
 PI2 = 5.1415926535897932384626433832795;
   E = 2.718281828459;

type
  TSinglePoint = record
    X,Y : single;
  end; 
  
  TMath_Func = PROCEDURE (var x: single);
  TXYVector = array[0..DIM] of TSinglePoint; 

var 
  fct1x, fct2x, fct3x, fct4x: TMath_Func;
  cFrm: TForm;
  fPoints: TXYVector;
  amp, freq: byte;


procedure drawChart(vPoints: TXYVector; vcolor: integer);
var
  i, hsize: integer;
begin
  with cFrm.canvas do begin
    hsize:= cFrm.Height -1 div 2;
    Pen.Color:= vcolor;
    MoveTo(0, hsize -((round(vPoints[0].Y))));
    for i:= 0 to DIM do
      LineTo(i, round(vPoints[i].Y));
  end;
end;  
  

procedure LoadForm;
begin
  cFrm:= TForm.create(self);
  with cFrm do begin
    caption:= 'maXFunCPlotter(((((\*/)))))';  
    BorderStyle:= bsDialog;
    height:= 440;
    width:= 800;
    color:= clblack;
    //onPaint:= @PaintBox1Paint;
    Show;
  end  
end;

//---------------------------ADD math functions---------------------------------  
//helmholtz
procedure fct4e(var x: single);  
begin
   //x:= power(E, -x);
     x:= -150*(power(x,2)/(power(30+power(x,2),2)));
end;

procedure fct5e(var x: single);
begin
     x:= 150*(power(x,2)/(power(30+power(x,2),2)));
end;

procedure fct3eSin(var x: single);
begin
  //power() means e^-x
   x:= power(E, -x) * (sin(pi2 * x));
end;

PROCEDURE fct1sin(var x: single);
BEGIN
   x:= Sin(pi2*x);
END;
  
PROCEDURE fct2cos(var x: single);
BEGIN
  x:= Cos(pi2*x);
END;

  
PROCEDURE fct_table(start, amp, freq, color: integer; FCT: TMath_Func;
                                         fct_name: string);
var x, tempx: single;
    origy, i: Integer;
BEGIN
  Writeln('x freq:  |   ' + inttostr(freq));
  origy:= cFrm.Height div 2;
  x:= start;
  for i:= 0 to (DIM) do begin
    x:= i/freq
    //Writeln(floatToStr(x))
    tempx:= x;
    FCT(x);
    fPoints[i].Y:= origy + (x * amp);
    //Writeln(floatToStr(x) +' | '+ floatToStr((tempx)));
  end;
  DrawChart(fPoints, color)
END;

procedure TFrmMain_Button1ClickTest(Sender: TObject);
var
  aHandle     : THandle;
  aFileSize   : Integer;
  aFileName   : String;
  afh: integer;
begin
    aFileName    :='C:\myfolder\myfile.ext';
    aHandle      := CreateFile(PChar(aFileName),GENERIC_READ, 0, '0', 
          OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0); // get the handle of the file
    try
        aFileSize:= GetFileSize2(aHandle,0); //get file size for use in the  lockfile function
        Win32Check(LockFile(aHandle,0,0,aFileSize,0)); //lock the file
        //your code
        //
        //
        //
        //getfilehandle
        afh:= fileopen(Exepath+'firstdemo.txt',0);
        writeln('handle '+inttostr(afh))
        fileclose(afh)
        
        Win32Check(UnlockFile(aHandle,0,0,aFileSize,0));//unlock the file
       //function FileUnlock(Handle: Integer; Offset, LockSize: Longint): Integer;
    finally
      CloseHandle(aHandle);//Close the handle of the file.
    end;

end;


 var a,b,i, afh: integer;
  
//main function_p call  
BEGIN
  //calls the proc with a function var
  ProcessMessagesON;
  amp:= 110;
  freq:= 440;
  loadForm
  fct1x:= @fct1sin
  fct2x:= @fct2cos
  fct3x:= @fct3eSin
  fct4x:= @fct4e;
  fct_table(40, amp, freq, clred, fct1x, 'Sin(x)');
  fct_table(50, amp, freq, clyellow, fct2x, 'Cos(x)');
  fct_table(30, amp, freq, cllime, fct3x, 'ESin(x)');
  //fct_table(30, amp, freq, clblue, fct4x, 'E(x)');
  // thread A 
  for i:= 10 to 50 do begin
    fct_table(40, 150, i, clblue, fct4x, 'HE(x)');
    fct_table(40, 150, i, clblue, @fct5e, 'HE(x)');
  end;
   //thread B
 // for i:= 10 to 50 do
  //fct_table(40, 150, i, clblue, @fct5e, 'HE(x)');

    writeln(floattostr(sin(90)))
    a:= 20; b:= 70;
    writeln(floattostr(a/b))
    
    maXcalcF('0.5*log(2)/log(2)+0.5*log(2)/log(2)')  
    //> 1
    maXcalcF('0.75*log(4/3)/log(2)+0.25*log(4)/log(2)')  
    //> 0.811278124459133

    //Application.CreateForm(TfrmMain, frmMain);
    //THexForm2
    //WM_DEVICECHANGE
    //WM_DEVICECHANGE
    //BoxMoveSelected
    //RegisterWindowMessage
      //sTMsg
     // MakeWParam
     //  SmallPointToPoint
       //tagMINMAXINFO
       //$MinMaxInfo
       //TWindowPos
      swapint(34) 
      playMP3(maXpath+'examples\maxbox.mp3');
      
      { afh:= fileopen(Exepath+'firstdemo.txt',0);
       fsz:= FileSize(Exepath+'firstdemo.txt');
        writeln('handle '+inttostr(afh))
       Win32Check(UnlockFile(afh,0,0,fsz,0));//unlock the file
      fileclose(afh)}
       
END.

Ref:

 procedure getScriptandRunAsk;
  var getstr, ascript: string;
  begin
   ascript:= 'http://www.softwareschule.ch/examples/demoscript.txt';
   if InputQuery('Get Web Script','Please enter the script path:',ascript) then
     begin
     //writeln('you entered: '+(string(ascript)));
    // wGet(ascript,'scriptdemo.txt');
     //writeln(ExtractFileNameOnly(ascript))
     //laz files
     getstr:= ExtractFileNameOnly(ascript)+'.txt';
     
     wGet(ascript,getstr);
     
    if MessageDlg('You want to run this script?'+#13#10+ascript,
            mtConfirmation,[mbYes,mbNo],0)=mrYes
    then begin
        ShellExecute3(ExePath+'maxbox3.exe',getstr,seCmdOpen)
        //statusline
    end else   
      showmessage('script start halted!');
     //www.softwareschule.ch/examples/demoscript.txt
    end;
  
  end;