Manual

Before you start painting, you can load an image as the background(By clicking open an image and select from your files). Note that either load an image or not is fine.
Outline your image with your mouse. Click left mouse button to add a point, and click right mouse to remove a point. The red point is the last one you have just added, while previous ones are yellow.

Click the calculate button after you have finished your painting. The epicyclical data will be computed and saved by this time.
There are some alternative sittings, which you can choose your preferences by clicking the settings button:

min circle size. This relates to the minimal size of the circle. Increase this value to get a simpler, and smoother curve. Decrease it to have a more accurate output.
speed. The speed of the animation displayed in the window.
max tracers. Maximum amount of the tracers.
interpolation. We use a linear interpolation algorithm to fetch more data of the input motion, whereas this can be configured. If you would like to have a better understanding about the calculation or have a smoother output, you can either switch to none or spline instead of linear.
data. The amount of output values in the interpolation algorithm.
sorted by radius. Select it to sort circle by their radius, otherwise default by frequency.

Once the calculation is finished, you can turn on the animation display by clicking show animation button. Note that this function rely on the last epicyclical data calculation, i. e., the data by the last time you press the calculate button.
Besides displaying on the screen, you can also export the animation as .gif or .mp4 files. Steps are:

Press export button.
If you would like to export as a mp4 movie, configure the fps and frames scale(where frames is the amount of frames of drawing the whole motion once) and click export as mp4 button. Select your directory and file to save, and... wait. It takes a while.
If you would like to export as an animated gif image, press the export as gif button. Due to the memory problem, the frames and fps of a gif is not available for configuration.
If you are interested in mathematical functions of the motion, click the export as text button.

Notice:

mp4 output requires your computer to have ffmpeg installed. If you haven't install a such software, the program will automatically download one to the default directory.
filter static circle means not to show a circle which is not moving.

This is a GPL Licensed software. While using and distributing, please follow the terms.

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