Welcome to the Markov - Applet

Usage Reference

How do I use it ... This reference supplies a short introduction on how to use the applet.

First troubleshooting - Why you may not be able to start the applet:

• Do you use Windows 3.x?
  Windows 3.x is not able to run Java-applets.

• Is your browser up to date?
  If your browser is of generation 3.0 or earlier, it is obsoleted. Those browsers do not understand Java.

• Did you enable Java within your browser options?
  Go to your Options-Menu and enable Java.

Start If your browser can handle Java a button with the inscription "Start Applet" is shown on the right. Use it to start the program. Shortly later, a window with the mainscreen opens. It is separated into three areas: On top there is a menubar ...

Sorry, no Java. Markov-API

(Note, appearance may vary depending on the browser and operating system you are using.)

with five entries. Furthermore, there is the mainscreen in center showing a startup message; as well the so called "rule-panel" on the right. Initially, it should read "no Rules available"

The Menubar

• Introduction presents a short overview to markov algorithm. To understand this completely you should be familiar with Semi-Thue-Systems, at least.

• Usage summarizes the most important information and provides a quick start.

• Example 1 shows one very simple example of a Markov-algorithm. A pattern is to be found within a given word.

• Example 2 is a more complex example unifying two sets of characters.

• Interpreter is the actual tool. More, below.

All buttons are supplied with a short discribtion (a kind of online help); This can be read in the statusbar while pointing at an item. (Note: Several errors and hints that might help are also shown via the statusbar on the buttom of the screen.)

Interpreter ... by clicking on this button a new window is presented. This is the interpreter or rule window for it provides a screen to enter own rules and hand them over to the actual interpreter. There are three simple steps to test an algorithm:

1. Type in your beginning word of your algorith in the top textfield:

2. Enter your rules in the center widget. Rules have the following format: l->r where l is the left side, r stands for the right side of the rule; and -> separates left from right side (The arrow -> must appear in every rule).
   If the empty word epsilon (sometimes also referred to as lambda) should be represented, write nothing.

   Example: A rule that removes every occurance of the letter "a" within a text (i.e. "a->epsilon") must be written as "a->". (The " are not part of the rule.)

   A stop rule looks like this: finished->.done. Here, the occurance of finished is replaced by done; and no other rule is applied after this one, because a dot right after -> marks the stop rule.

   It is also important to use one line for every rule, only. (If you think this is difficult load one of the examples into this rule window and experiment with the syntax of the rules.)

   Comments (a whole line starting with --) as well as blank lines my be included anywhere within the code; they are ignored by the interpreter.

3. Click on the Button to hand over your rules to the interpreter and to start the algorithm.
   If an error should occure (i.e. no beginning word is given, your rules are syntactical wrong, ...) a message is shown via the statusbar.

Also, within this rule-window the two preprepared examples may be loaded and tested immediately by using one of the buttons.

There is an additional button with the inscription "from URL". Using it, a new window appears within you may specify a www-side containing a Markov-Algorithm. This is loaded right into the rule-window. (Any errors that might occure will be shown via the statusline.)

Running ... if the rule-window was closed via "Apply Rules" and all rules are correct, they are printed on the right panel. Furthermore, the mainscreen is initialised with the beginning word.
Now, use these buttons to apply one rule or twenty rules at once.

Contacting the author ... For questions or comments write an email to Alexander Theel using the following address alex.theel@gmx.net.