How to constantly update a plot off of a slider being pulled

Is it possible to automatically update a graph based off of the slider. I now how to update the graph once the position in the slider has changed, but what I want to know is it possible to have the graph up date as the slider is being pulled. Essentially, as the slider is being pulled, I want the graph to update for each position that the slider value cross, not just update once the slider is let go off and one set value is made. Does anyone have any ideas how to do this?

[Srikanth Kothamasu]

I have two curves one is actual like (y=mx^2),other one is simulated curve which will be having similar behavior but not follow the actual one. so now i have to fallow the first curve with the help of slider is that possible. if so can you help out.

Answer 1

[Teja Muppirala]

I know what you are trying to do, I often want to do the same

Save the following in a file and run it to see an example:

function myslider
x = 1:10;
hplot = plot(x,0*x);
h = uicontrol('style','slider','units','pixel','position',[20 20 300 20]);
addlistener(h,'ActionEvent',@(hObject, event) makeplot(hObject, event,x,hplot));

function makeplot(hObject,event,x,hplot)
n = get(hObject,'Value');
set(hplot,'ydata',x.^n);
drawnow;

[Lawson Hoover]

Thank you for helping me! I was looking into the java stuff and I just wouldn't have the time to learn all that. What I am not fully clear on is:

@(hObject, event) mzkdplot(hObject, event,x,hplot));

[zero]

Actually, I don't think you have plot the result with "real time". For the same result as yours, we could still use the "Callback" function of uicontrol. A good answer, while a perfect solution to "real time". Of course, I have not solved it, and still try.

[Amanda K Hanson]

if you use uislider, you can use a value changED function (which would do what you already have) or a value changING function (which it appears you want). more info at https://www.mathworks.com/help/matlab/ref/uislider.html

If youre set on using uicontrol's slider, I'm not sure how to update it constantly.

[JP Schnyder]

Since Matlab 2014a, 'ActionEvent' is renamed to 'ContinuousValueChange'in

addlistener(h,'ActionEvent',@(hObject, event) makeplot(hObject, event,x,hplot));

Answer 2

[Matt Fig]

Yes.

function [] = slider_plot()
% Plot different plots according to slider location.

S.fh = figure('units','pixels',...
              'position',[300 300 300 300],...
              'menubar','none',...
              'name','slider_plot',...
              'numbertitle','off',...
              'resize','off');    
S.x = 0:.01:1;  % For plotting.         
S.ax = axes('unit','pix',...
            'position',[20 80 260 210]);
S.LN = plot(S.x,S.x,'r');        
S.sl = uicontrol('style','slide',...
                 'unit','pix',...
                 'position',[20 10 260 30],...
                 'min',1,'max',10,'val',1,...
                 'sliderstep',[1/20 1/20],...
                 'callback',{@sl_call,S});  

function [] = sl_call(varargin)
% Callback for the slider.
[h,S] = varargin{[1,3]};  % calling handle and data structure.
set(S.LN,'ydata',S.x.^get(h,'value'))

[Lawson Hoover]

Right I now how to this, In fact I am already using that for the slider. What I am looking for is as you pull the slider, without actually letting go of it, the graph with update constantly. So if the slider starts at val 1 and then is drag to val 3 it seamlessly changes the graph from val 1 to val 2 to val 3 as the slider value crosses over that value.

[Matt Fig]

Oh I see. You mean if you click-and-hold on the slider knob itself and drag it instead of clicking in the trough. In that case, I don't think you can do it without accessing the underlying JAVA. The callback will not fire until a buttonrelease event.

Sorry, but I don't see any way to do it in pure MATLAB.

[Lawson Hoover]

Oh, ok, I was thinking that it had to do something with java. How hard would it be to do that? I have not really messed around with the java aspect of MATLAB yet.