Matlab program files for wavelet analysis
Programs from Introduction to Wavelets and Wavelet Transforms, A Primer by Burrus, Gopinath, and Guo (1998).
Sound recording on Silicon Graphics machines
A good source for .wav files is a home computer running Windows.
Use Find to search for files with extension .wav.
Use Matlab as below to read the files.
Basic instructions for making recordings and converting to a format Matlab can read
wavelets.wav and a.wav are data files that Matlab can read.
They are recordings of Craig Zirbel saying "wavelets" and long "a".
Make your browser download them (for example by right clicking on the link).
wavelets.m is a Matlab file that reads the two data files above, displays the signal, and displays their Fourier energy spectrum.
Spectrograms on sigma
The BG Unix machine sigma runs Matlab 5.0, which has a nice signal
OhioSeis Station BGO is the homepage
of the OhioSeis Digital Seismographic Station located in Bowling Green,
Ohio. This station is part of the Ohio Seismic Network.
Robert Vincent of BGSU brought this to my attention.
Directory of BGO data is the
directory of seismic data from the Bowling Green station.
Note that times listed there are Universal Time (UT), which is 4 hours
ahead of Eastern time in the summer, 5 hours ahead in the winter.
The lines of the data files are separated by the character ^M, which
Netscape and Matlab treat properly (see the example seismic.m below).
Each data file has a header which must be removed.
It consists of the first 80 lines of the file and ends with the text "data:
The numbers in the data files are vertical displacements of the spring in
the seismometer, measured in micrometers.
aBGSOZIP1999.09.21.18 is the
dataset covering the 2:00 PM to 3:00 PM hour on the afternoon of September
21. (The first wavelet talk of the semester began at 2:30 PM on that day.)
The header has been removed.
seismic.m loads and graphs the seismic data file
From the graph, it appears that nothing seismic occurred at 2:30 on that day!
Examples of wavelet transforms