MATLAB: Save plot every second in different file image

plotsavetimer

Please Help me.

I have the program of monitoring signal which I use plot function to view the signal. Because I use the timer function, the plot changed every second. What I want is I can save that plot for every second, let say for 10 seconds. What will I to do so the plots are saved in a file with different named? say file 1.tiff for signal 1, file 2.tiff for signal 2, and so on.

Best Answer

Hi,

in the function which is called from the timer (TimerFcn callback) before updating the plot you can save it. Lets say the TimerFcn is named

timer('TimerFcn',@my_func, 'Period', 1.0);

Than you create my_func as follows

function my_func(obj,event )

This will pass the timer object to my_func in every call. The timer object has a property called 'TasksExecuted'. With this property you can create dynamic file names easily as follows:

%before updating the plot
print(handle_to_plot,'-dtiff',['signal_',num2str(get(obj,'TasksExecuted'))]);
%update plot

More specific:

t = timer('TimerFcn',@my_func, 'Period', 1.0,'ExecutionMode','fixedRate');
start(t);
function my_func(obj,event )
get(obj,'TasksExecuted')
end

Related Solutions

MATLAB: How to make a timer execute an internal function in gui

When you use a string to designate a function in a callback, then the string is eval()'d in a context equivalent to the base workspace, outside of any hierarchy. Only functions that are built-in or which have .m on the path can be accessed that way.

You should switch to using a function handle. Also, you need to make an adjustment for the fact that you are not expecting the standard parameters in your callback

handles.t = timer('BusyMode', 'queue', 'ExecutionMode',...
'fixedRate', 'Period', 4.0);
set(handles.t, 'TimerFcn', @(hObject, event) funkcija(event, handles));

Note that the handles variable that will be passed in to the callback will contain exactly whatever the handles structure contained at the time the anonymous function was created. The reason for splitting the assignment of handles.t and the setting of TimerFcn is that splitting it allows the timer handle itself to be recorded in the handles structure before that version of the structure is "frozen" for the purposes of the anonymous function.

If you want the current version of the handles object to be passed in to the function at the time the timer is fired, then the easiest route is to pass in information that allows you to figure out where the handle structure is. For example, you could use

handles.t = timer('BusyMode', 'queue', 'ExecutionMode',...
'fixedRate', 'Period', 4.0, 'TimerFcn', @funkcija);

with

 function funkcija(hObject, EventData)
   handles = guidata(hObject);
   a = 1;

MATLAB: Varying timer’s period inside the TimerFcn

This page mentions an approach to vary the period of timer: https://stackoverflow.com/questions/15576682/matlab-change-repeating-timer-period

Here I show the method mentioned in the second answer. This example sets a random time period between 1 to 5 seconds after each callback of timer.

t = timer('StartDelay', 1, 'TimerFcn', @timerFcn, ...
    'StopFcn', @timerStopFcn, 'ExecutionMode', 'singleShot');
start(t);
function timerFcn(obj, ~)
    disp(obj.StartDelay)
end
function timerStopFcn(obj, ~)
    period = randi([1 5]);
    obj.StartDelay = period;
    start(obj);
end

Best Answer

Related Solutions

MATLAB: How to make a timer execute an internal function in gui

MATLAB: Varying timer’s period inside the TimerFcn

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