Convert Logitech K380 Qwerty Keyboard into Dvorak

I used to type on Dvorak layout. But, it's very difficult today to get Dvorak layout on any keyboard by default. So I have habit to disassembly all of my new device keyboard (MacBook Pro, PC, standalone keyboard).

This K380 is no exception, :)

This keyboard is using butterfly mechanism, so it's easy to disassembly it, :)


 

Using 'Home-Made' Fortran Binary as Python module

Python is easy to use, but it's slow, especially for loop computation. So I compute it using fortran like this

        subroutine subs(a, b, n)
        double precision a(n)
        double precision b(n)
        integer n
cf2py   intent(in) :: a
cf2py   intent(out) :: b
cf2py   intent(hide) :: n
!        b(1) = a(1)
        do 100 i=2, n
                b(i) = a(i)-1
100     continue
        end

save it as aravir.py and do the following command

$ f2py -c aravir.f -m aravir

To use the module on the python I use the code below

import numpy as np
import aravir as ar

a = np.linspace(0,1,100)

b = ar.subs(a)

print a
print b

:)

Asus Eee PC won't Enter BIOS

Got this Eee PC without OS. 

Planned to install it myself. 

This netbook don’t have cd drive. 

so the choice is via pxeboot or flash/thumb drive. 

(have set PXE boot several month ago for CentOS, and have no desire to do it again or my head will split :) ) 

so via flash drive then 

we could use any thumb drive and any iso, given it have enough space

we could make this pen drive bootable with any tool (windowsbased, linux via dd, os x based, unix based) just google for it

Okay

what now

First, we must set BIOS of this netbook to boot via USB drive

to enter BIOS we must press F2 after powered this device on

…

…

or maybe F1

…

…

ESC

…

…

DEL

…

…

F12

…

err, it seem I couldn’t get bios interface. Googling around and found out that I have to repeat the press on F2 fast

and, hooray…

succeed, installed OS on it

but, wait

my OS is 32bit

I have 4GB RAM on this eee PC and 32bit OS generally could only handle 3.6GB RAM, oh my…

…

download 64bit iso

make it bootable on flashdrive

reinstall the OS, but…. it won’t enter BIOS, again

no mater how fast I press F2 key it’ll always go to OS boot 

same thing happenend to del, esc, F1, F12 keys

…

:(

…

(wish for luck)

grab external usb keyboard

plug it on

press power, press F2 and, tadaa…, oh my God, that BIOS interface…

…

(reinstalling)

…

now my ASUS Eee PC have 64bit OS on it

:)

 

My device is Asus eeepc x200ca-kx190d 1007/4g/500g/dos/blu

Laggy Mavericks and QuickLook that Neither Quick nor Look on Anything

Don't know what happened, but my Maverick is getting slower and slower.

QuickLook can't preview .f,  .py and .tex files (and other files type too as I tried to "quick-looking" other type but fortran, python and latex  is what I "quick-looking" most).

Monte Carlo PI

 
c    calculating pi by throwing stones
c
 PROGRAM stones
 IMPLICIT none
c
c    declarations
 REAL*8 area, x, y, DRAND48
 INTEGER i, max, pi, seed
c
c    set parameters (number of stones, seed for generator)
 max = 1000
 seed = 11168
c
c    open file, set initial value, seed generator
 OPEN(6, FILE='pif.dat')
 pi=0
 call seed48(seed)
c
c    execute
 DO 10 i=1, max
    x = DRAND48()*2-1
    y = DRAND48()*2-1 
    IF ((x*x + y*y) .LT. 1) THEN
       pi = pi+1
    ENDIF
    area = 4.0 * pi/REAL(i)
    WRITE(6,*) i, area
 10  CONTINUE
  STOP
  END

PI on MPI

still trying...

 program main
      include "mpif.h"
      double precision  PI25DT
      parameter        (PI25DT = 3.141592653589793238462643d0)
      double precision  mypi, pi, h, sum, x, f, a
      integer n, myid, numprocs, i, ierr
c                                 function to integrate
      f(a) = 4.d0 / (1.d0 + a*a)

      call MPI_INIT(ierr)
      call MPI_COMM_RANK(MPI_COMM_WORLD, myid, ierr)
      call MPI_COMM_SIZE(MPI_COMM_WORLD, numprocs, ierr)


 10   if ( myid .eq. 0 ) then
         print *, 'Enter the number of intervals: (0 quits) '
         read(*,*) n
      endif
c                                 broadcast n
      call MPI_BCAST(n,1,MPI_INTEGER,0,MPI_COMM_WORLD,ierr)
c                                 check for quit signal
      if ( n .le. 0 ) goto 30
c                                 calculate the interval size
      h = 1.0d0/n
      sum  = 0.0d0
      do 20 i = myid+1, n, numprocs
         x = h * (dble(i) - 0.5d0)
         sum = sum + f(x)
 20   continue
      mypi = h * sum
c                                 collect all the partial sums
      call MPI_REDUCE(mypi,pi,1,MPI_DOUBLE_PRECISION,MPI_SUM,0, 
     &                  MPI_COMM_WORLD,ierr)
c                                 node 0 prints the answer.
      if (myid .eq. 0) then
         print *, 'pi is ', pi, ' Error is', abs(pi - PI25DT)
      endif
      goto 10
 30   call MPI_FINALIZE(ierr)
      stop
      end

Hello Canvas World

canvas's not supported
Back to first again
Tulisan di atas ditulis dalam canvas seperti kode di bawah. Di sini perintahnya adalah

context.fillText('Hello Canvas World',canvas.width/2-150,canvas.height/2+15);

context adalah '2d' dari canvas, dalam hal ini context kotak yang menyimpan perintah-perintah '2d' canvas seperti contoh diatas, yaitu menulis text.

fillText('tulisan', posisi_x,posisi_y) adalah perintah untuk menampilkan tulisan dengan warna sesuai fillStyle, yaitu 'green'

strokeText('tulisan', posisi_x,posisi_y) adalah perintah untuk menampilkan tulisan dengan warna 'tepi' sesuai strokeStyle yaitu 'red'

var  canvas = document.getElementById('canvasexample'),
 context = canvas.getContext('2d');

context.font = '38pt Arial';
context.fillStyle = 'green';
context.strokeStyle = 'red';

context.fillText('Hello Canvas',canvas.width/2-150,canvas.height/2+15);
context.strokeText('Hello Canvas',canvas.width/2-150,canvas.height/2+15);

Mountain Lion's Spotlight didn't Spot Application

Maybe it's just me, after upgrading from leopard to snowleopard to lion and finally mountain lion (always upgrade, no fresh install), this big cat suddenly refuse to index my Application. Whenever I type application name in Spotlight, it just show document, picture but not Application. Typing "macvim" bring me to macvim installation folder, macvim on the web but not Macvim apps. Spotlight setting clearly didn't ban Application folder, so maybe this is another Mountain Lion problem

Still looking for solution...

Mountain Lion's Fullscreen Apps on Extended Display

It seems that weakness of this big cat isn't resolved yet. I used Pages in my Desktop while the big one browsing trough web using safari for refence. When I switch (automatically, bad behaviour I think) to fullscreen on Pages, suddenly the other display become blank (not actually blank, just linen-like wall, or maybe canvas).

Playing with Opacity on HTML5's canvas

 What I do here is wrap whole canvas on this program with a rectangle with opacity 0.1. So the code (under script tag) become like this:

var context;
var x=100;
var y=200;
var dx=5;
var dy=5;
var n=10;
var bBola=new Array();
function init(){
 canvas=myCanvas;
 context= myCanvas.getContext('2d');
 for (i=0;i &lt n;i++){
  dx = Math.random()*10-5;
  dy = Math.random()*10-5;
  bBola.push(new bola('#007700', 11,dx,dy));
 } 
 setInterval(draw,10);

}

function draw(){
   for (i=0;i &lt n;i++){
   if (bBola[i].x &gt = (canvas.width - bBola[i].r) || bBola[i].x &lt = bBola[i].r) bBola[i].dx *= -1;
  if (bBola[i].y &gt = (canvas.height - bBola[i].r) || bBola[i].y &lt = bBola[i].r) bBola[i].dy *= -1;

  //buat
  bBola[i].context.beginPath();
      bBola[i].context.fillStyle = bBola[i].color;
      bBola[i].context.arc(bBola[i].x,bBola[i].y,bBola[i].r,0,Math.PI*2,false);
  bBola[i].context.fill();
   
  //gerak
      bBola[i].x+=bBola[i].dx;
  bBola[i].y+=bBola[i].dy;
 }
 
 context.fillStyle='rgba(255,255,255,.1)';
 context.fillRect(0,0,canvas.width,canvas.height);
}

function bola(color, r,dx,dy){
     this.canvas  = canvas;
     this.context = canvas.getContext('2d');
     this.r  = r;
     this.x =Math.random()*400+30;
     this.y  = Math.random()*250+30;
     this.dx  = dx;
     this.dy  = dy;
     this.color   = color;
}

window.onload = function(){
        init()
}

Here the complete html page code




<head>
<script>
var context;
var x=100;
var y=200;
var dx=5;
var dy=5;
var n=10;
var bBola=new Array();
function init(){
canvas=myCanvas;
context= myCanvas.getContext('2d');
for (i=0;i<n;i++){
dx = Math.random()*10-5;
dy = Math.random()*10-5;
bBola.push(new bola('#007700', 11,dx,dy));
} 
setInterval(draw,10);

}

function draw(){
 for (i=0;i<n;i++){
//pantul
  if (bBola[i].x >= (canvas.width - bBola[i].r) || bBola[i].x <= bBola[i].r) bBola[i].dx *= -1;
if (bBola[i].y >= (canvas.height - bBola[i].r) || bBola[i].y <= bBola[i].r) bBola[i].dy *= -1;

//buat
bBola[i].context.beginPath();
    bBola[i].context.fillStyle = bBola[i].color;
    bBola[i].context.arc(bBola[i].x,bBola[i].y,bBola[i].r,0,Math.PI*2,false);
bBola[i].context.fill();

//gerak
    bBola[i].x+=bBola[i].dx;
bBola[i].y+=bBola[i].dy;
}

context.fillStyle='rgba(255,255,255,.1)';
context.fillRect(0,0,canvas.width,canvas.height);
}

function bola(color, r,dx,dy){
    this.canvas  = canvas;
    this.context = canvas.getContext('2d');
    this.r  = r;
    this.x =Math.random()*400+30;
    this.y  = Math.random()*250+30;
    this.dx  = dx;
    this.dy  = dy;
    this.color   = color;
}

window.onload = function(){
        init()
}
</script>
</head>
<body>
<canvas height="300" id="myCanvas" width="500">
</canvas>
</body>

Gradient on HTML5's Canvas

Bouncing Ball using Array on Canvas (without prototype method) in HTML 5

Here the code for this




<head>
<script>
var context;
var x=100;
var y=200;
var dx=5;
var dy=5;
var n=5;
var bBola=new Array();
function init(){
canvas=myCanvas;
context= myCanvas.getContext('2d');
for (i=0;i<n;i++){
dx = Math.random()*10-5;
dy = Math.random()*10-5;
bBola.push(new bola('#007700', 17,dx,dy));
}
setInterval(draw,10);

}

function draw(){
  context.clearRect(0,0, 500,300);
  for (i=0;i<n;i++){
//pantul
  if (bBola[i].x >= (canvas.width - bBola[i].r) || bBola[i].x <= bBola[i].r) bBola[i].dx *= -1;
    if (bBola[i].y >= (canvas.height - bBola[i].r) || bBola[i].y <= bBola[i].r) bBola[i].dy *= -1;
//buat
bBola[i].context.beginPath();
    bBola[i].context.fillStyle = bBola[i].color;
    bBola[i].context.arc(bBola[i].x,bBola[i].y,bBola[i].r,0,Math.PI*2,false);
    bBola[i].context.fill();
//gerak
    bBola[i].x+=bBola[i].dx;
bBola[i].y+=bBola[i].dy;
}
}

function bola(color, r,dx,dy){
    this.canvas  = canvas;
    this.context = canvas.getContext('2d');
    this.r  = r;
    this.x =Math.random()*400+30;
    this.y  = Math.random()*250+30;
    this.dx  = dx;
    this.dy  = dy;
    this.color   = color;
}


window.onload = function(){
        init()
}
</script>
</head>
<body>
<canvas height="300" id="myCanvas" width="500">
</canvas>
</body>

Random Text in HTML 5 using Array and Canvas

The Bouncing Ball

The Code for this under the script tag

var context;
var x=100;
var y=200;
var dx=5;
var dy=5;

function init(){
 canvas=myCanvas;
 context= myCanvas.getContext('2d');
 setInterval(draw,10);
 bal=new bola('#007700', 17,dx,dy);
}

function draw(){
   context.clearRect(0,0, 300,300);
   bal.Pantul();
   bal.Create();
   bal.x+=bal.dx;
   bal.y+=bal.dy;
}

function bola(color, r,dx,dy){
     this.canvas  = canvas;
     this.context = canvas.getContext('2d');
     this.r  = r;
     this.x =Math.random()*400+30;
     this.y  = Math.random()*250+30;
     this.dx  = dx;
     this.dy  = dy;
     this.color   = color;
}

bola.prototype.Create = function (){
     this.context.beginPath();
     this.context.fillStyle = this.color;
     this.context.arc(this.x,this.y,this.r,0,Math.PI*2,false);
     this.context.fill();
}

bola.prototype.Pantul = function (){
 if (this.x >= (canvas.width - this.r) || this.x <= this.r) this.dx *= -1;
     if (this.y >= (canvas.height - this.r) || this.y <= this.r) this.dy *= -1; 
}

window.onload = function(){
        init()
}

Bouncing Ball in HTML 5 using Canvas Method

A Result of Trial and Error

Here the code

Bouncing Ball using Array in HTML5

I want to create bouncing ball program that's very easy on Flash, Python or Delphi yet very tricky on html5. The program consist of n ball with random velocity (each) moving in a 2d box (oh yeah, square then :) ) 

I am playing with array in html5 script which is helpful on this program. I don't declare the array using

aBola = new array()

that come  as standart on many language, but prefer

aBola = []

instead, just like list on python. In this program, array's just like container for ball.

In html5, moving an object is a bit tricky and, for some Pascal programmer like me, bringing an old memory of draw-clear-draw-clear... cycle; draw a ball, delete it, draw the same ball but slightly right, delet it, ... and so on. All that kind of tedious job, but it worth for the sake of fast execution and no-need-slow-loading-flash-player thing.

Here's the code under script tag. Keep in mind that many variable's name is in indonesian (ball -> bola, bounce->pantul, collision -> tumbukan )

 
 //bola:ball
 //pantul:bounce
  var context;
  var n=10;

   // membuat bola 
   function bola(color, r,dx,dy){
      this.canvas  = canvas;
      this.context = canvas.getContext('2d');
      this.r  = r;
      this.x =Math.random()*400+30;
      this.y  = Math.random()*250+30;
      this.dx  = dx;
      this.dy  = dy;
      this.color   = color;
   }

   bola.prototype.Create = function (){
      this.context.beginPath();
      this.context.fillStyle = this.color;
      this.context.arc(this.x,this.y,this.r,0,Math.PI*2,false);
      this.context.fill();
   }
   bola.prototype.Pantul = function (){
  if (this.x >= (canvas.width - this.r) || this.x <= this.r) this.dx *= -1;
      if (this.y >= (canvas.height - this.r) || this.y <= this.r) this.dy *= -1; 
   }
   function init(){
    canvas  = document.getElementById("myCanvas")
      context = canvas.getContext('2d');
  // membuat array untuk bola
  //create array for ball
      aBola = [];
  for (i=1;i<=n;i++){
   //membuat bola sejumlah n dengan dx dan dy acak
   //create n balls with random dx and dy
   dx = Math.random()*10-5;
   dy = Math.random()*10-5;
       aBola.push(new bola('#007700', 17,dx,dy)); 
      }
         setInterval(draw,20);
   }
   function draw(){
      context.clearRect(0,0, 500,350);
  for (i in aBola) {
   //menggerakkan bola
   //moving balls
         aBola[i].x += aBola[i].dx;
         aBola[i].y += aBola[i].dy;
         aBola[i].Pantul();
         aBola[i].Create();
       }
    }

(to be continued)

2D/3D Ball Collision

I used on 1D collission problem where, in case of elastic collision, the ball is changing velocity each other. In 2D/3D case however, the collision is not always head-on collision (which is basically 1 dimension collision).

Head-on

The system above's easy too solve, as simple as interchanging velocity (in elastic case).




Not head-on

When two balls are in non-head-on collision we could always using transposed new coordinate where both of ball center are on the new x-axis like below

On the new coordinate, we can treat the velocities along x-axis as one dimensional collision case and let go on other component (y, z) intact.

Below's snippet from python code of balls collision detection; the whole code is code of moving many ball on a box.

###deteksi tumbukan antar bola
for i in arange(jumlah):
  for j in arange(i+1,jumlah):
    jarak=mag(lbola[i].pos-lbola[j].pos)
    if jarak<(lbola[i].radius+lbola[j].radius):
      arah=norm(lbola[j].pos-lbola[i].pos)
      vi=dot(lbola[i].v,arah)
      vj=dot(lbola[j].v,arah)
      tukar=vj-vi
      lbola[i].v=lbola[i].v+tukar*arah
      lbola[j].v=lbola[j].v-tukar*arah
      pantul=lbola[i].radius+lbola[j].radius-jarak
      lbola[i].pos=lbola[i].pos-pantul*arah
      lbola[j].pos=lbola[j].pos+pantul*arah

Moving to HTML5

After years fighting the slow loading flash without alternative software, I begin to think seriously about moving to HTML5 coding. Altough it ain't true software for me, it provide what I need mostly: animation.

HTML5 support canvas, audio ad video tag, javascript. Need array data? No problem. If then else? OK.

So, begin...

Array di Delphi

Array dapat digunakan sebagai penyimpanan sementara. Array dapat dipandang sebagai sebuah variabel yang berisi barisan variabel di dalamnya.

Berikut adalah contoh penggunaan array di delphi sekaligus penggunaan listbox dan radiobutton.



Buat sebuah form dengan satu edit, satu button, satut listbox dan tiga radiobutton.

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    RadioButton1: TRadioButton;
    RadioButton2: TRadioButton;
    ListBox1: TListBox;
    RadioButton3: TRadioButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  nama:array [0..100] of string;
  n:integer;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  radiobutton1.Caption:='input';
  radiobutton2.Caption:='tampilkan';
  radiobutton3.Caption:='semua';
  edit1.Text:='';
  radiobutton1.Checked:=true;
  button1.Caption:='OK';
  n:=0;
end;

procedure TForm1.Button1Click(Sender: TObject);
var i:integer;
begin
    if (radiobutton1.Checked=true) and not(edit1.Text='') then begin
      listbox1.Items.add(edit1.Text);
      n:=n+1;
      nama[n]:=edit1.Text;
    end;
    if radiobutton2.Checked=true then begin
      listbox1.Clear;
      if (edit1.Text<='9') and (edit1.Text>='0') and not(edit1.Text='') then begin
        listbox1.Items.Add(nama[strtoint(edit1.Text)]);
      end;
    end;
    if radiobutton3.Checked=true then begin
      listbox1.Clear;
      for i:=1 to n do begin
        listbox1.Items.Append(nama[i]);
      end;
    end;
end;

end.