% Spectrum of Real Data
% 
% DATASPECT starts with no data.  Import data to the function by pressing 
% the button "load WAV" for data stored in a .WAV file, or "load TXT" for
% a .TXT file, or "load variable" for a main workspace array.  On Macintosh
% computers, there will also be a "load Sound" button for Mac sound files.
% The .WAV and Mac sound formats have the sampling frequency fs built-in. 
% In the case of a .TXT file or a workspace variable, fs must be specified.
% A .TXT file should contain a single column of data in one of the Matlab-
% recognized text formats.  When Matlab loads a text file the file name 
% enters the workspace, so the file name must not conflict with Matlab 
% keywords, especially "eval" and "clear." 
% Users of the Student Edition of Matlab will be limited to importing data
% sets no longer than 16,384 samples.
%
% Push the "Play Sound" button for audio output.
%
% The data series is displayed in the upper, data axis.  Use the popup
% menu to select a window form to apply to the data.  Different windows
% may or may not improve the quality of the spectrum, depending on 
% circumstances.  The window is not applied to audio output.  The
% "Kaiser 2.5" window is defined using alpha=2.5, equivalent to using
% beta=7.85 in KAISER, in the Matlab signal toolbox.
%
% A check box activates the Matlab zoom controls for both axes.
%
% The lower, spectrum axis displays the Discrete Fourier Transform of the 
% data as an Amplitude, Power, Complex, or Decibel spectrum.  Pushing the 
% "Return" button returns the frequency array and the spectrum array to the 
% main workspace.  Note that the DFT value at zero frequency is twice the 
% mean of the signal (using window "None").
% 
% DATASPECT(Y,FS) starts with the data array Y and the sampling 
% frequency scalar FS.
%
% DataSpect checks the Matlab search path to see if its location is
% on the path.  If not, the location is added to the path, but this 
% change is not permanently saved.
% 
% See also FOURCOEF, FUNSPECT, FIRSTORD, SECONDORD, 
% MULTISYS, and SAMPLING.
%
