Notes on J-DSP

J-DSP is a digital signal processing toolkit written in Java, and made available on the World Wide Web at the following address:

http://www.eas.asu.edu/~spanias

J-DSP allows you to manipulate most discrete-time signals, including long-term signals such as music, or human speech. It comes with the ability to define most discrete-time signals, apply filters to them, and perform various operations upon them, such as plotting them, or convolving two signals together. A brief example follows:

This is a screenshot of a basic DSP setup in the program. To the far left are two signal generators.

This is the first signal, a simple triangular wave represented in thirty samples.

And this is the second signal. Note that this is the same triangular wave as before, except inverted.

When one assembles the block as seen in the beginning screenshot, then double-clicks upon the Plot2 box, this is what comes up. On the left is a continuous-time representation of the convolution of the two triangle-waves. On the right, is a frequency-domain representation of the same thing. To obtain the frequency-domain requires inserting a FFT block between the convolution and the plot boxes. J-DSP allows you to specify any number of points to do the transform over, from 8 to 256!

Overall this program seems to be very interesting. With further experimentation, one could find many applications for this toolkit.