Notes on codes, projects and everything
We were asked to develop a program that demonstrate Artificial Intelligence and apply what we had learned in class into the program. Then we came out with an idea to develop a program that is able to do tarot reading. At first the program did not have a GUI and is operated through Swi-Prolog interpreter but in the end we included a GUI-frontend for the program using XPCE.
First the program will require 3 random numbers from the user, then a random number will be generated as the seed. Then the card will be “shuffled” (in fact, we did some calculations to the user provided random numbers) and then determine the orientation of the card (normal and reversed). Then, we use the computed number to pick a tarot card and get the reading based on the orientation.
To shuffle the cards, we use a random number and place the random number into the formula such that $$c=x^y\text{ mod }23$$ where c is the corresponding card number, x is the user provided number and y is the system generated random number. Then the orientation of the card is determine by calculating the mod 2 of the random number.
To implement simple search strategy, we used a hash function to divide the total of 22 major arcana cards into 5 groups. Each group will have one individual database file storing the card characteristics and reading. Then, depending on the calculated number, the system will choose to query which database file to decrease the inclusion of database files. We may not be able to observe the performance enhancement as we only have 5 database files but it should be more obvious for system with more database files.
I am the developer for the GUI front-end. At first we planned to write the GUI using other languages/platforms but because of the time constraint we decided to give up on GUI front-end. However, I managed to pick up basic XPCE GUI construction just in time and made a GUI for the program. However, the GUI is not very friendly and is not able to display images. Because XPCE is a multi-platform supported toolkit therefore the appearance of the GUI is consistent in various supported operating system.
The program is reading input through prolog interpreter.
The program displays the result after computing the input.
The program is reading input through GUI
The program displays the result through the GUI
While JSON is a fine data-interchange format, however it does have some limitations. It is well-known for its simplicity, that even a non-programmer can easily compose a JSON file (but humanity will surprise you IRL). Therefore, it is found almost everywhere, from numerous web APIs, to geospatial data (GeoJSON), and even semantic web (RDF/JSON).
To do node selection for DOM operations, one typically uses CSS selectors as (probably) popularized by jQuery. However, there is another alternative that is as powerful if not better known as XPath. XPath may be able to do a lot more than just selecting node (which I have no time to find out for now) but I will just focus on how to do node selection in this blog post.
Traversing a tree structure often involves writing a recursive function. However, Python isn’t the best language for this purpose. Therefore I started flattening the tree into a key-value dictonary structure. Logically it is still a tree, but it is physically stored as a dictionary. Therefore it is now easier to write a simple loop to traverse it.
I was thinking whether it is possible to avoid exposing PDO and PDOStatement objects to the users of my database library (mainly just me). While I was working on my project I sort of notice that there is a almost fixed pattern whenever I work with the database. With this in mind, I added in some new functions to the library, and decided to make a quick release for this.
After comparing my own implementation of MVC with CodeIgniter’s, now I’m comparing Kohana’s and Zend’s. I have just shifted from CodeIgniter to Kohana recently in work and is currently learning on how to use Zend Framework to build my web-app. As everybody knows, Zend Framework is more like a collection of library classes than a framework a la Ruby on Rails, using MVC in Zend Framework would require one to begin from bootstrapping stage. However, in Kohana, just like other frameworks, bootstrapping is done by the framework itself so the developer will get an installation that almost just works (after a little bit of configuration).