MATLAB: Slider in GUI

guislider

Hello

I'm having trouble getting a slider to work in a GUI.

I currently have 1 slider in my GUI, that is suposed to change its values everytime a different variable is chosen in a popupmenu.

After a certain variable is chosen, the slider Min and Max properties would be changed to the variable Min and Max and the slider should run through all the variable values.

I've tried to change the slider Min, Max and Step properties by writing

set(handles.slider1,'Max',variableMax);
set(handles.slider1,'Min',variableMin);

but its not working.

Is it possible to make the slider work this way? And if it is, how can i do it?

Thanks in advance.

Sara

Best Answer

not working? how can we help if you don't provide enough details (error message at least), please be sure that variablemax and min are numbers (use str2num if it's a string) not strings or a cell. Also remeber to update the handles structure after setting the new values.

prompt = {'Enter min:','Enter max:'};
dlg_title = 'min=?,max=?';
num_lines = 1;
def = {'0','1'};
answer = inputdlg(prompt,dlg_title,num_lines,def);
%answer is a cell with two strings
%You must choose the cell element answer{n} , that gives you the string
%first one is the min and the second is the max
%Now you need to convert string to number, that can be done using str2num
variableMin=str2num(answer{1});
variableMax=str2num(answer{2});
set(handles.slider1,'Max',variableMax);
set(handles.slider1,'Min',variableMin);
% Update handles structure
guidata(hObject, handles);

Related Solutions

MATLAB: Slider is still at min and not moving

Yeah, because you're setting the value equal to the min every time the user tried to slide it. Remove this line to fix it:

set(handles.slider1, 'Value', sliderMin); % set to beginning of sequence

MATLAB: Fix Values of a slider in GUI to be multiple of two

vittorio - you can try discretizing the slider values as at https://www.mathworks.com/matlabcentral/answers/153278-discretizing-matlab-slider-gui. If you know how many values or steps you want in your slider, you could do in the OpeningFcn

 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);

In the slider callback, you would then multiply your slider value by two

 function respondToContSlideCallback(hObject, eventdata)
 % 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);
    % calculate the new number of points
    numPoints = 2 * get(hObject, 'Value');
 end

Best Answer

Related Solutions

MATLAB: Slider is still at min and not moving

MATLAB: Fix Values of a slider in GUI to be multiple of two

Related Question