Problem with plotting using a GUI and Simulink

I am trying to Plot realtime position data On to a GUI axes. My first attempt was using a listner function but i could only plot the data if i used the method of

s=plot(x_data,y_data) set(s,'Parent',axes2)

This would result in the data being plotted but i could not discover a way of keeping my axis fixed at the point [-1,1,-1,1] for the x and y limits.The plot would shift to the amount of change in the data.

To try and overcome this i started using timer functions which would activate at a period of 0.01 seconds that would call the data from simulink.

Again i came up with the same problem. with also a further problem is that the plot would not automatically update. I had to use a push button to force update it. This makes little sense to me as the function on the timer should carry on doing this.

Can anyone help with any of my problems ? My code is below.

% --- Executes on button press in plot_data. function plot_data_Callback(hObject, eventdata, handles) % hObject handle to plot_data (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) axis_plotter=timer; set(axis_plotter,'executionmode','fixedRate') set(axis_plotter,'Period',0.01) set(axis_plotter,'TimerFcn',@plot_axis) start(axis_plotter)

      function plot_axis(source,event)
    global new_xdata
    global new_ydata

    rto = get_param('manualflight/2dplot','RuntimeObject'); 
    ydata = rto.InputPort(1).Data ;
    xdata = rto.InputPort(2).Data ;

      new_xdata=[xdata,new_xdata];
      new_ydata=[ydata,new_ydata];    
        set(axes2.handles, 'XLim', [-1,1], 'YLim', [-1,1])    
      set(axes2.handles,'XData',new_xData,'YData',new_yData);

I also tried

     --- Executes on button press in plot_data.
    function plot_data_Callback(hObject, eventdata, handles)
    % hObject    handle to plot_data (see GCBO)
    % eventdata  reserved - to be defined in a future version of MATLAB
    % handles    structure with handles and user data (see GUIDATA)
    axis_plotter=timer;
    set(axis_plotter,'executionmode','fixedRate')
    set(axis_plotter,'Period',0.01)
    set(axis_plotter,'TimerFcn',@plot_axis)
    start(axis_plotter)

        function plot_axis(source,event)
      global new_xdata
      global new_ydata

      rto = get_param('manualflight/2dplot','RuntimeObject'); 
      data = rto.InputPort(1).Data ;
      xdata = rto.InputPort(2).Data ;

        new_xdata=[xdata,new_xdata];
        new_ydata=[ydata,new_ydata];    

          b=plot(new_xdata,new_ydata);  
            set(b,'Parent',axes2)      
         drawnow update

This code came up with the problem of not updating and having a too small of an axis

Answer 1

[Kaustubha Govind]

You need to register Simulink execution event listeners for the plot to update as the simulation runs. See Listening for Method Execution Events and How can I update a GUI with values from my Simulink model as it is running?

[Paul]

I have done this before.

And again I came up with the same problem that The Plot of the axis when created shrinks down to very small movements.

As my data can see a change in movement of 1 millimeter. While the plotting area i want it in is in the space of 4 meteres squared.

[Kaustubha Govind]

I don't know a lot about MATLAB graphics, but it seems that there should be a MATLAB-based solutions to this problem. I was examining the demo that I pointed to above, and I see that they use "drawnow('expose');" to update the plot - I don't know if the "expose" parameter does anything to prevent resizing of the plot. Do you use the same parameter with DRAWNOW?

[Paul]

I dont seem to be able to find the file of this demo . or the line of code your refering too.

[Kaustubha Govind]

Is it possible you have an older version of MATLAB before the demo was introduced? In any case, I was wondering if replacing "drawnow update" with "drawnow expose" might change anything.

[Paul]

I went back to your earlier advice and used listners.

At first it worked perfectly . Now for some reason the listener function is failing to be called even though the event listener is active on the desired block. The simulation is running smoothly it just seems that this function is never called although it does not seem to call any errors.

Below is the code i have used

set_param('manualflight','StartFcn','localAddEventListener');

function eventhandle=localAddEventListener

eventhandle=add_exec_event_listener('manualflight/2dplot','PostDerivatives',@LocalEventListner);

function LocalEventListner(block,eventdata)

global new_xdata % makes new_x data a global point

global new_ydata % make new_y data a global thing

xdata = (block.InputPort(1).Data); %imports x data from simulink

ydata = (block.InputPort(2).Data); %imports y data from simulink

new_xdata=[xdata,new_xdata]; %adds the new point to the x data array for plotting

new_ydata=[ydata,new_ydata]; %adds the new point to the y data array for plotting

%get a handle to the GUI's 'current state' window

statestxt % plots the the xy data that has been pulled

axis ([-1 1 -1 1])

% fixes the axis to the area of the vicon area

This is quite confusing as it seemed to be working perfectly last night. I then decided to work on some other things in the night and came back to test it again today and for some reason the second function seem to be failed being called.

I suspected I may had written a function i forgot about somewhere and forot about it . but when i icilated all the files on a different machine the same probelm occured.

Am i missing something very simple ?

[Kaustubha Govind]

Are you still running your model in Normal mode? Someone on this forum mentioned recently that event listeners don't work in Accelerator mode (although I can't find this mentioned in the documentation).