MATLAB: How to move slider-bar with a step-size of two

guiguidematlab guislider

Hey there everyone. I have a slider which I want to increase like 1:2:10 by dragging the bar with mouse. How can I accomplish that?

Thanks in advance!

Best Answer

Round the Value property to the nearest value in your array in the callback function.

allowed_vals=1:2:10;%better: store this in the guidata struct
val=3.2;%val=get(hObject,'Value');
[~,idx]=min(abs(allowed_vals-val));
val_rounded=allowed_vals(idx);
%set(hObject,'Value',val_rounded);
disp(val_rounded)

Related Solutions

MATLAB: Discretizing matlab slider GUI

Hamad - you will have to add some code in order to discretize the slider for the case where you slide the "slider" without using the arrows. In the yourGuiName_OpeningFcn of a GUI named yourGuiName, I added the following code

 function yourGuiName_OpeningFcn(hObject, eventdata, handles, varargin)
 handles.output = hObject;
 % add a continuous value change listener
 if ~isfield(handles,'hListener')
    handles.hListener = ...
        addlistener(handles.slider1,'ContinuousValueChange',@respondToContSlideCallback);
 end
 % set the slider range and step size
 numSteps = 13;
 set(handles.slider1, 'Min', 1);
 set(handles.slider1, 'Max', numSteps);
 set(handles.slider1, 'Value', 1);
 set(handles.slider1, 'SliderStep', [1/(numSteps-1) , 1/(numSteps-1) ]);
 % save the current/last slider value
 handles.lastSliderVal = get(handles.slider1,'Value');
 % Update handles structure
 guidata(hObject, handles);

I'm not sure if you are using the slider Callback or have created something similar to the above which is more flexible. So all we've done is to create the listener, initialized the slider, and updated the handles structure.

Now we have to define the callback, respondToContSlideCallback as

 % --- Executes on slider movement.
 function respondToContSlideCallback(hObject, eventdata)
 % hObject    handle to slider1 (see GCBO)
 % eventdata  reserved - to be defined in a future version of MATLAB
 % Hints: get(hObject,'Value') returns position of slider
 %        get(hObject,'Min') and get(hObject,'Max') to determine range of slider
 % first we need the handles structure which we can get from hObject
 handles = guidata(hObject);
 % get the slider value and convert it to the nearest integer that is less
 % than this value
 newVal = floor(get(hObject,'Value'));
 % set the slider value to this integer which will be in the set {1,2,3,...,12,13}
 set(hObject,'Value',newVal);
 % now only do something in response to the slider movement if the 
 % new value is different from the last slider value
 if newVal ~= handles.lastSliderVal
     % it is different, so we have moved up or down from the previous integer
     % save the new value
     handles.lastSliderVal = newVal;
     guidata(hObject,handles);
    % display the current value of the slider
    disp(['at slider value ' num2str(get(hObject,'Value'))]);
 end

Now when you run the code, you will only see the integer values being written to the Command Window whenever you use the slider arrow buttons or manually move the slider. The difference between each integer will always be one. So we ignore any "slides" in between any two consecutive integers.

Try the above and see what happens!

MATLAB: Handling Slider in GUI

Setting the min and max and sliderstep should be done at the time the slider is created, such as in slider2_CreateFcn

For the other part of your question see https://www.mathworks.com/matlabcentral/answers/216723-how-can-i-force-a-slider-uicontrol-object-in-guide-to-move-in-discrete-steps

Best Answer

Related Solutions

MATLAB: Discretizing matlab slider GUI

MATLAB: Handling Slider in GUI

Related Question