How do you change the X-axis to update in real time on a plot in a live data acquisition GUI?

I am working on a GUI with several plots showing data acquired in real time. Plot 1 (attached below) starts with a small range on the x-axis. Then, during the three seconds of data acquisition, the axis grows as the data is plotted to reach a range from 0 to 3 seconds. Plot 2 (also attached below) starts with a range from 0 to 0.1 seconds. During data acquisition, Plot 2 moves through the 3 seconds in 0.1 second increments, from 0 to 0.1 all the way until it reaches 2.9 to 3.0 seconds. I would like Plot 2 to behave the same way as Plot 1, starting with a small range which then expands as data is acquired to show the full range from 0 to 3 seconds. I am having trouble because the code I use to generate these plots is almost identical.

Here is the code:

s = daq.createSession('ni');
ch = addAnalogInputChannel(s, 'Dev1', 0:2, 'Voltage');
ch(1).TerminalConfig = 'SingleEnded';ch(2).TerminalConfig = 'SingleEnded';
s.DurationInSeconds = 3;
s.Rate = 1000;

dataListener1 = addlistener(s, 'DataAvailable', @(src, event) datamanager(src, event));

startBackground(s)    

hGui.Fig = figure('Name','Live GUI', ...
 'NumberTitle', 'off', 'Resize', 'on', 'Position', [10 50 1900 950]);

%Code for Plot 1
hGui.Axes1 = axes;
set(hGui.Axes1, 'Units', 'Pixels', 'Position',  [200 200 450 100]);

%Code for Plot 2
hGui.Axes2 = axes;
set(hGui.Axes2, 'Units', 'Pixels', 'Position',  [200 50 450 100]);

function datamanager(src, event, varargin)
hGui.DataPlot1=plot(hGui.Axes1, event.TimeStamps, event.Data(:,1),'.k') ; hold on
hGui.DataPlot2=plot(hGui.Axes2, event.TimeStamps, event.Data(:,2),'.k') ; hold on
end

One thing that happens is when I comment out the Code for Plot 1, Plot 1 disappears and Plot 2 works as I want it to, starting with a small range and expanding as data is acquired to show the full 0 to 3 seconds range. I'm not sure why that is. Any insight on how to get Plot 2 to work like Plot 1 would be great. Thanks!

Answer 1

[Geoff Hayes]

Eamon - perhaps the hold isn't being applied to the second axes when both are being updated. Try being explicit about which axes you want to apply the hold to. For example,

 hold(hGui.Axes1 ,'on');
 hold(hGui.Axes2 ,'on');

instead of the

 hold on;

in your above code.

[Eamon]

Works like a charm. Thanks for the help!