by DM » Mon Dec 01, 2008 12:36 am
Hi
A Lissajous figure plots two changing signals each on the X and Y axes. In audio it is often used to display phase relationships in a stereo signal. For instance, if you had a stereo signal of 1000Hz in each channel and those signals were in phase, you would get a diagonal line in the display both signal would rise and fall at the same time). If the signals are 180 degrees OUT of Phase, then the figure would be a circle.
If the signals are not the same frequency, you get more interesting patterns: With signal such as 1000Hz and 500 Hz, you would get a type of fisgure eight. If you usem say 1000Hz and 499 hz, the you would get a figure eight the slowly rotates at 1 Hz...
With normal stereo signal, the effect cabn range from wild scribbling (fast, uncorrolated left and right channels) to slow, changing ovals and figure eights with more static low sounds.
This may be a more technical explaination than necessary. On an Old Skool oscilloscope it was very easy. One would attach the left channel to the x axis and the Right channel to the Y axis and off you go!
But you are right, the figure looks a little like the Belzier curves.
Perhaps R4 is more involved than I need (though it is just so beautiful!) I just need to plot the relationship of two signals on a cartesian plane... is this 2D request too simple for R4 or is it (or perhaps I) just too simple for R4?
Dave