stripchart_documentation.m

%% STRIPCHART Create a stripchart for real-time data display
%
% STRIPCHART makes it fairly easy to include a strip chart in your
% real-time data acquisition and analysis application.  You feed
% stripchart your data, and it updates the display.  It takes
% 2 steps to use STRIPCHART.  First, you initialize the stripchart with basic
% information needed for the FFT (sample rate, axis width, number of traces).
% After that, all you need to do is pass your data to the stripchart to update.
%
% This documentation starts with the simplest syntax for the two steps,
% then provides a few more advanced options.

%% STEP 1: Initialize the stripchart
% STRIPCHART(FS,AXESWIDTH) initializes a stripchart in the current axes.
% This stripchart will display incoming data with a sample rate of FS Hz.
% The stripchart will display the most recent AXESWIDTH seconds of data.

%% STEP 2: Update the stripchart
% STRIPCHART(S) updates the stripchart in the current axes with the
% data in vector S.  The stripchart should first be initialized as above with
% sample rate and axes width.  If not, the sample rate will be 1 Hz and the
% axes width will match the duration of S.  

%% Including multiple traces
% STRIPCHART(FS,AXESWIDTH,NTRACES) initializes a stripchart in the
% current axes with NTRACES traces.  A trace is a single line on the stripchart;
% typically one will display one trace per channel of data.  The default
% for NTRACES is 1. To update a stripchart with multiple traces,
% STRIPCHART(S) must specify a matrix S with shorter dimension length =
% NTRACES.  

%% Specifying the axes to locate the stripchart
% STRIPCHART(HAX, ...) defines the stripchart in specified axes HAX instead of GCA.  i.e.,
% STRIPCHART(HAX,FS,AXESWIDTH) initializes axes HAX as a stripchart, and
% STRIPCHART(HAX,S) updates axes HAX with vector S.

%% Returning a handle to the stripchart
% HAX = STRIPCHART(...) returns a handle to the axes initialized by the
% stripchart.  This is useful if you allow STRIPCHART to create an
% axes for you, and want to be able to easily reference the axes for
% updates.  The lines created by STRIPCHART all have the tag
% 'StripChart'.  If you would like to manually modify the properties of
% these lines, their handles can be found by:
%
%           HAX = STRIPCHART(...);
%           HLINE = findobj(HAX,'Tag','StripChart');
%
%% Example
% Create data
Fs = 1000;                      % Sample rate
Ns = Fs*3;                      % Make 5 seconds worth of data
t = (0:1:Ns-1)'/Fs;
A = sqrt(t);
A(1:Ns/2) = A(1:Ns/2);
A(end:-1:Ns/2+1) = A(1:Ns/2);
s = A.*sin(2*pi*t*1);

%%
% Initialize stripchart
clf
AxesWidth = 2;                  % Axes Width (s)
stripchart(Fs,AxesWidth);

%%
% Update stripchart
N = 50;
ind = 1:N:Ns;

for ii = ind
    stripchart(s(ii:ii+N-1,:));
    drawnow;pause(.05);
end;

% Copyright 2004 The MathWorks, Inc