using linkdata on existing figures

I have a gui that displays a movie frame by frame.

There are also plots of various data pertaining to the movie in separate figures.

I would like to link the plots to the movie frame time and display a vertical line on any existing figures that is located at the current movie frame time.

the code I am trying is various forms of:

%%get list of current figures:

fig_list = findobj('Type','figure')

figure(fig_list(1)) %%first fig only right now

ylims = get(gca,'YLim');

h1 = plot([systime_value systime_value], [ylims]);

linkdata(h1, 'on')

This prints a vertical line at the current time, but I get errors on the linkdata part, and the line is redrawn every iteration.

I am also running this from a subfunction that passes in "systime_value". Maybe this is the problem?

Thanks for any input.

Answer 1

[Walter Roberson]

http://www.mathworks.com/help/techdoc/ref/linkdata.html

When a figure containing graphs is linked and any variable identified as XDataSource, YDataSource, and/or ZDataSource changes its values in the workspace, all graphs displaying it in that and other linked figures automatically update.

In your code, I do not see that you have set any *DataSource variable.

[Art]

Walter - at various times I have tried including

set(h1,'XDataSource','systime_value')

after the plot command.

I still get an error.

[Art]

Actually, I think I may be able to do this without using linkdata at all. If I just update the XData value each time through the line updates as I want it to.

Thanks

Answer 2

[Scott]

Came across this and it helped me, but here is what I did in my GUI.

My GUI contains several input fields, buttons and one axes that I named plot1 and want to update as data arrives or is taken.

My opening function for the gui initializes the plot and links the data.

function MyGuiName_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to VoltageRamp (see VARARGIN)

% Choose default command line output for VoltageRamp
handles.output = hObject;

% Create variables and timer objeect
handles.xData=[];
handles.yData=[];

% Initialize the plot, then define and link the data sources
plot(handles.plot1,1,1,'LineWidth',2);
set(get(handles.plot1,'Children'),'XDataSource','handles.xData');
set(get(handles.plot1,'Children'),'YDataSource','handles.yData');
linkdata on;

% hide the stupid banner that pops up to show that data is linked
dpm=datamanager.linkplotmanager;
dpm.Figures.Panel.close;

% Update handles structure
guidata(hObject, handles);

Then any time I update handles.xData and handles.yData, the plot will update. In my case, a timer object updates them periodically and a few different buttons update them on demand. Just don't forget to issue guidata(hObject, handles); after a callback has retrieved and updated the variables.

[Scott]

also don't forget to 'refreshdata(handles.figure1,'caller')' to force a refresh of your GUI. This is similar to using 'drawnow'.