Ploting analog input in real time
2 visualizzazioni (ultimi 30 giorni)
Mostra commenti meno recenti
Hey evereyone I have the following code
input=analoginput('winsound'); set (input, 'SampleRate', 8000); set (input, 'SamplesPerTrigger', 1000); num=1000; set (input, 'TriggerRepeat', inf); start(input)
while "something" data = getdata(input); flushdata(input); plot("data"); plot("fft data spectrum") stop(input) delete(input); end
The data plot shows fine, but the second plot will only show something for 1 second just after i run the code and then it shows nothing. Why is that happening?
0 Commenti
Risposte (2)
Gautam Vallabha
il 8 Dic 2011
It is possible that one of your plots is being overwritten by the other plot. The standard plot command (plot(x,y)) uses the current figure and axes (gcf and gca), the default behavior is that a new plot will replace any existing plots.
You might try explicitly using different axes, e.g.
ax1 = subplot(2,1,1);
ax2 = subplot(2,1,2);
while (...)
plot(ax1, time, amplitude);
...
plot(ax2, freq, power);
end
By the way, for better performance, instead of calling plot each time, consider calling it once (before the while loop), and then setting xdata and ydata, e.g.:
h = plot(ax1, time, amplitude);
...
set(h,'xdata', newTimeData, 'ydata', newAmplitudeData);
Walter Roberson
il 8 Dic 2011
Do not stop() and delete() input within the loop.
Within the loop, add a drawnow() call after the plot() call.
5 Commenti
Walter Roberson
il 9 Dic 2011
Please see my comment to my answer in http://www.mathworks.com/matlabcentral/answers/22208-show-figure
Vedere anche
Categorie
Scopri di più su Graphics Performance in Help Center e File Exchange
Prodotti
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!