Drawing board

Lemon city
Lemon city

When I was on university we had a PC application for creating geometrical drawings. As I already knew about software development at that time, I was very very impressed by that application.

Was 20 years ago, internet was not yet there at that time, but I did not forget about the program and you can still download it from the company which is developing and selling it.

A couple of years ago, when I had to learn JavaScript, the language for the internet browser, I decided to combine learning with some fun. But it took me much longer than I would have been willing to invest. After a some months, a break of about some years and a restart, here is the result: www.lemon.city

The difficulty was finding out how to do the geometrical calculations! I never really had vector calculation in school. What I know about it is from some lessons on university. But I was able to find for most of the problems solutions. Some solved in this way, some solved in that way. Once I will come back and read a book about vector calculation and create a new library!

Some features are still missing from the original solution I worked with 20 year ago. But I am already very proud about what I were able to realize. When there is the next time slot where I have enough time, I will continue, for sure.

Bug catcher

BugCatcher
BugCatcher

Tried to develop a small app similar to Minekeeper, a game I was playing endlessly when I was a young developer.

Here is the result: a joker can be used to get help. Clicking longer on a cell sets a flag on it.

If a cell which does not contain any surrounding mines is clicked, the cell and all surrounding cells are opened as well.

Try it here: BugCatcher …

 

Head First jQuery

Monster
Monster

From time to time you have to learn something new. If you go to bed and think about what you have learned today and there comes nothing into your mind. Stand up and read something in a lexicon just to be able to say that you have learned something that day.

Currently I am back on learning something for my job. jQuery is a development language for internet development, a library which makes it easy to develop web pages able to be running in different browsers.

I bought a book and started reading chapter after chapter until I came to this nice chapter about programming a monster page where you can swap images to define the face of numerous different monsters. Click here to see the page I have developed with help of that book. Many thanks to the writers of the book for the images and the idea!

Mandelbrot in Excel

Mandelbrot Excel
Mandelbrot Excel

Here is the result. It took me only minutes to implement it and as you can see in the different sheets, I have also implemented the Julia set in the same workbook.

The sheets are for 3 different resolutions and you see that the range where both sets are visible is from -2.2 / -1.5 to 0.8 / 1.5 for the Mandelbrot set and from -1.8 / -1.5 to 1.8 / 1.5 for the Julia Set.

I realized the different colors with conditional formatting which is a nice feature of Microsoft Excel. Points which are part of the set are black, points which are not part of the set are colored. The color depends on the number of iterations necessary to decide that they are diverting and is going from red and yellow to white.

You can download the Excel workbook from here. You might have to allow the basic script!

Julia Set

Julier Set
Julier Set

I am a fan of the Mandelbrot set since I have seen it the first time. I developed a screen saver for windows which displays the Mandelbrot set and zooms in randomly.

I also tried to develop something similar for the iPhone but did not succeed for the time. When I was investigating possibilities to draw lines in HTML code, I saw that with HTML 5 there is a new tag <Canvas> which allows exactly what I need.

Here is the result. I have created a page which shows the Mandelbrot set and the same for the Julia set. Both are very impressive. You can zoom in by clicking somewhere in the graph and even move the graph with the mouse.

Here is the page with the Mandelbrot set and
here is the page with the Julia Set.

iPhone development

Triangle
Triangle

Since I have an iPhone, my wish was to create my own iPhone application. But not so easy as I immediately saw.

First, you have to have a MAC where you can install the iPhone development studio. This was the biggest problem. I buyed an old MAC on ebay but found out, that the MAC I had bought was to old. And after three months it died.

Months later I had the opportunity to buy a Netbook from a friend. And the guy had installed MAC OS on this Netbook. So the biggest hurdle was taken.

The rest was quite simple. For an experienced developer it is not so hard, to learn a new development language within a few days. And after two week or so, I were able to publish my first application.

The application is similar to something I already did years ago for PCs. It is a software which draws a triangle. You can move the corners of the triangle and the most important special points, lines and circles of a triangle are drawn.

Mandelbrot

Mandelbrot
Mandelbrot

A long time ago I was impressed from this bizarre images made of the mandelbrot set. And a few weeks ago I developed a screensaver which draws different details of the mandelbrot set.

Meanwhile I know a little bit more about this image and it is much more fascinating than ever before. I invested at lot of time to get this screensaver running. But now it works. It randomly selects a part of the currently painted image and zooms inside this part. The zooming goes on until the computer is not able to calculate more detailed information.

You can download the screensaver Mandelbrot and copy the file into the system directory. Then select the screensaver in the desktop property screen and make some odd settings there. You will enjoy it and be impressed of the different images of the Mandelbrot set.

Triangle

Triangle
Triangle

When I attended school and had some lessons about the triangle I was deeply impressed from this odd figure.

And since I tried some calculations with vector analysis my idea was to develope a screensaver which randomly draws a triangle and calculates and paints all important points, lines and circles of the triangle.

You can download the screensaver Triangle and copy the file into the system directory.