Using set to update graphs in matlab

Question

I'm trying to update new values to a function using the 'set' function.

Here is the code:

daq_object = analoginput('winsound');
chan = addchannel(daq_object,1);
x=[10];
num_samples = 1000;
axes(handles.axes1);
plot_handle=surf(T,F,10*log10(P),'edgecolor','none'); 
axis tight; 
view(0,90);
xlabel('Time (Seconds)'); ylabel('Hz');

 set(daq_object,'SamplesPerTrigger',inf,'SamplesAcquiredFcnCount',num_samples,...
    'SamplesAcquiredFcn',{@update_plot,handles});

function update_plot(handles)

data = getdata(daq_object,num_samples);
[S,F,T,P] = spectrogram(data,256,250,256,1E3);

    set(plot_handle,'YData',T,F,P); % ERROR WITH THIS, UPDATING THE VARIABLES. 

end

The error is that, I don't know how to update multiple variables in a function. for one variable ex:

h=plot(zeros(100,2));
for i=1:20
    set(h,'Ydata',rand(10,1));
    drawnow;
end

but here I need to update the T,F and P values. How can I use SET to do that?

I tried:

set(plot_handle,'YData',T,F,P);

but thats just giving me errors.

Your example uses analoginput from the Data Acquisition toolbox. Since many people who might answer you (including myself) don't have access to this toolbox, could your provide an example which uses base MATLAB? — Richie Cotton

Richie Cotton Richie Cotton · Accepted Answer · 2011-07-26T12:30:47

set takes name-value pairs, that is, after the first variable (which is a handle to a figure or some axes), the arguments need to alternate name of variable, then value to assign to that variable.

In your example that failed you have three consecutive values (T, F and P) without names in between.

Using set to update graphs in matlab

1 Answers