Spirograph, Fun Visualising Mathematical Functions

very good
key review info
application features
  • save as file
  • (2 more, see all...)

As a kid, I used to watch the Spirograph commercials on TV and remember wanting to mess around with it. Years have past, I am now all grown up, but I have yet to play with a real life spirograph. Fortunately, I have come across the next best thing. SpirographX is a program that lets you play with a virtual spirograph, adjusting it in real time, and animate it if you wish. For those of you who do not know what a spirograph looks like, just take a look at the screenshots. The SpirographX package actually contains two items, the SpirographX application itself, and a screen-saver.

Playing with spirographs When you first open up the SpirographX application you will find the display window, in which you can see the default spirograph that is always loaded at application start and the control palette.

The display window cannot be closed and is always present. Although it may not be very obvious at first, it can be resized like any window. Inside this window you can see the result of the parameters you play with in the Control Palette. Unfortunately there is no option to zoom in or pan around so your spirograph will only be as big as the window, and the window is only as big as the resolution and your screen real estate permits.

The Control Palette is split up into three tabs: Equation, Appearance and Animation. The Equation tab lets you define the way the spirograph will come out by letting you tweak variables in the equation that generates them. The base value dictates the proportion between each loop and the loop inside it. Whole numbers will generate solid, symmetrical patterns, while fractions will generate less solid ones, and the more complex the number is, the more chaotic the pattern will be. The number of subloops dictates the number of loops in the image. In general, the more subloops, the more random the image will look. Two loops will generate a regular spirograph and one will generate a circle. Cycles represent how many times you want to 'go around the circle' and draw the graph. Adding more cycles will make the drawing denser, but if you go overboard, the graph will become 'fractured', especially if your base is very close to a whole number. Also, if you have a slow computer, more cycles will mean more processing is required and it will be much slower. Finally, the detail value dictates how many points are plotted per radian. The higher it is, the smoother the curves will be, a value of 1 producing only lines and sharp angles.

Under the appearance tab you can change the way the lines that make up the spirograph look. There are 2 variables: the line and the blur, which is like a glow around the line. For each of these you can choose a width and a color, complete with opacity.

Under the Animation tab you can choose whether you want the graph animated. The animation slowly changes the base value within the range that you specify, so if you had a base of 1 and a range of 0.2, the animation would draw the graph between the values of 0.8 and 1.2. The speed value determines how fast the animation will be and is not a constant.

Saving screens with spirographs After playing with the program for quite some time and making some groovy spirographs I immediately proceeded to the system preferences to use them as a screen-saver. I placed the screen-saver module in its place in the system to install it and selected the SpirographX screen-saver. Sure enough, the little preview was showing spinning animations that promised hours of psychedelic visualizations based on mathematical functions that I really hated back in high school.

Unfortunately, the screen-saver will always display a random spirograph and the only options given to us are: Time Interval, which dictates the number of seconds between the generation of another spirograph, the lowest setting being 1 second and the highest about half a minute; and Detail, which will make the graphs smoother the higher it goes. A great disappointment. It would have been nice to be able to choose a spirograph from either a file or one of your favorites.

The Good Generate and animate spirographs easy, with just few clicks. Fine control over the shape of the graph that come out keeps you in charge and offers a large number of graphing possibilities.

The Bad The screen-saver is useless, when it could have been superb. Also saving as anything other than a SpirographX file is unreliable at best. You can export the current frame as an TIFF image but other than the name you have no options, and the resulting image will be the size of the Spiro View window. Very disappointing.

The Truth A neat little application which will provide hours of fascination if you have any interest in spirographs. It could definitely use a few improvements but it is by no means any less groovy.

Here are some screenshots, click to enlarge:

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user interface 3
features 4
ease of use 5
pricing / value 5


final rating 4
Editor's review
very good
 
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