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FrAid demos and ideas

Note
If you are a first time FrAid user first try the Flash demos on this page which offer a step by step overview of the FrAid controls and features. The Java applets bellow provide a more hands-on experience and actual FrAid interaction.

Those marked with a headphones sign will play sound trhough your audio system.

Flash Demos
3D Transformations Differential Equations Digital Filter Design Fractals in the Complex Plane



"Simple" Fractals Sampled Functions and Real Time Processing Real Time Processing

Java Applets
2D Graphics 3D Graphics Demo Fractals Mathematics



MIDI Differential Equations
and Nonlinear Dynamics

Animated GIF-s

Note
All of the signals captured in this section come from a regular stereo receiver whose line-out is connected to the line-in of the sound card.

Real Time Spectrogram of human voice:


Real Time Oscillogram of two signals - original and (Low Pass) filtered in real time:


Real Time Fast Fourier Transform:


Multiple of these can be used at the same time (the example bellow has an Oscillogram, a Histogram, a Spectrogram and a Fourier Transform Plot):

Output calibration (oscilloscope comparison)

The mapping of signals from the sound card to actual voltage is not only dependent on the current audio settings of the system but also the sound card model, the driver used and even the type and version operating system. FrAid overcomes this problem by calibrating the individual plots (i.e. the output) instead of the input (the input signal is allways being mapped to double precision numbers in the interval [-1,1]). FrAid plots can be calibrated with either a reference source or an external meter using the functions: 

                calibrate( plotWindowNumberToBeCalibrated, actualValue, measuredFunction );
                calibrateLike( plotWindowNumberToBeCalibrated, referencePlotWindowNumber );

whose defintions are provided in preload.frd

Note
All signals bellow were generated by a FrAid script and captured using:

gg(x)=recordSound( 10000, 2048 );
plot(gg);
plot({abs(fft1(gg))});

while the line-out of the sound card is connected to the line-in.

Sine Wave

Amplitude

OscilloscopeFrAid real time plot

Fourier Transform

OscilloscopeFrAid real time plot
Note
Oscilloscope's FFT amplitude scale is logarithmic while FrAid's is linear.

Triangle Wave

Amplitude

OscilloscopeFrAid real time plot

Fourier Transform

OscilloscopeFrAid real time plot
Note
Oscilloscope's FFT amplitude scale is logarithmic while FrAid's is linear.

Complex Wave

Amplitude

OscilloscopeFrAid real time plot

Fourier Transform

OscilloscopeFrAid real time plot
Note
Oscilloscope's FFT amplitude scale is logarithmic while FrAid's is linear.