Chart Programs 1.0
Daniel F. Smith, 1993/4/5 (dfsmith@cr1.see.plym.ac.uk)

These are some little programs that display charts for waveforms in
a window.  They're all simple and if you need to know details, read
the source.  The waveforms are assumed to be unsigned bytes.  Although
the programs shouldn't be platform specific, they were tested and run
only on a machine running Linux (Intel 486 based unix).

To make the programs:
  type make
You won't need to play with xmkmf/imake, but you may need to play with
the Makefile a bit if you have a peculiar setup for compiling X Athena Widget
applications.  I've included binaries for Linux anyway.

xchart
This program simply displays files in chart form in a scrolly window.  If
you display a file more than 65000 pixels wide, you may have scrolling
problems.  Complain to the Athena project or zoom out a bit.
Syntax example: xchart *.wav
		xchart wave1 wave2 wave3

xscope
This program chucks stdin into a window.  If you supply an argument then it
will multiplex the stdin into several `channels' (first byte into the first
window, second byte into the second window, etc.).  If you want to play with
real-time scope things on your sound card, then I suggest you write a little
program (it's about 10 lines) to call the /dev/dsp ioctls to set up the number
of channels and sampling rate.
Syntax example:	xscope </dev/dsp
		xscope 2 </dev/dsp		(in stereo)
		xscope </vmlinuz		(it's your funeral)
		xscope 8 </dev/mplex		(on my machine)

xfft
And this program chucks blocked stdin through a fast fourier transform
routine before putting it in the window.  You can use the floating-point fft
routines or integer ones.  I wrote the integer routines after I found out
the the 486DX runs the floating-point fft routines about 50 times faster
than my lowly 486SX.  Play with the Makefile to use FP.
Syntax example:	xfft </dev/dsp
		xfft </vmlinuz

Motivation: I built myself an 8-channel 400kHz analog to digital converter
for my research and wanted something that would show me what's happening.
The lab oscilloscope kept wondering off to nearby benches which made life
tricky when I wanted to find out why my circuits weren't working.  The fft
program was just to show off my integer fft routines though.

I'm putting these programs into the public domain.  Please be nice
and acknowledge me in your source code if you re-use the routines.  I'd
be delighted if someone added cut and paste to the Chart widget though.
--
Centre for Research in Information Storage Technology (CRIST), SECEE,
University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK.
