MATLAB: Is it possible to rotate a slider 180 degrees

vertical slider top-down

Hello,

I have a vertical slider, is it possible to rotate it 180 degrees?. The problem is that when I move the slider from top to down the value decreases and I would need the value increases when I move the slider from top to down.

Thank you

Silvia

Best Answer

This is easy, when you consider the different values inside the callback:

function ExampleSlider
sliderH = uicontrol('Style', 'slider', 'position', [10, 10, 20, 100], ...
                    'Min', 0, 'Max', 1, 'Callback', @CB);
function CB(ObjH, EventData)
value = get(ObjH, 'Value');
disp(value)

Now 1 is written to the command window, if you drag the slider to the top, and 0 for the bottom. Now change the callback to:

function CB(ObjH, EventData)
value = 1 - get(ObjH, 'Value');
disp(value)

E voila, 0 appears for the top and 1 for the bottom. There is no need to rotate the slider, but changing the logic to interpret the slider position is enough.

Related Solutions

MATLAB: Increasing slider value of a GUI

See https://www.mathworks.com/help/matlab/ref/uicontrol-properties.html#property_SliderStep

figure;
uicontrol('Style', 'Slider', 'Position', [10, 10, 200,20], ...
          'SliderStep', [1/29, 0.1], ...
          'Min', 10, 'Max', 300, 'Value', 10, ...
          'Callback', 'disp(get(gcbo, ''Value''))')

The range goes from 10 to 300, which is a distance of 290. To get a stepsize of 10, the SliderStep must be 10/290, or 1/29. You should expect rounding errors, so fix the value in the callback:

uicontrol('Style', 'Slider', 'Position', [10, 10, 200,20], ...
          'SliderStep', [1/29, 0.1], ...
          'Min', 10, 'Max', 300, 'Value', 10, ...
          'Callback', mySliderCB);
function mySliderCB(SliderH, EventData)
Value = round(get(SliderH, 'Value'));
set(SliderH, 'Value', Value);
...

MATLAB: How to Change the Min property of slider

When you set the 'Min' value to 1, the current 'Value' is still at 0. Therefore you should see the warning:

Warning: slider control can not have a Value outside of Min/Max range
Control will not be rendered until all of its parameter values are valid

Considering this:

function test4()  
hfig = figure();
slider = uicontrol('Parent', hfig,...
                'Style', 'Slider',...
                'Tag', 'slider1',...
                'Callback', @slider_callback,...
                'Min', 1, 'Max', 40,...
                'Value', 1, ...               % <- Inside [Min, Max]
                'SliderStep', [1/40 10/40]);  % Perhaps [1/39, 10/39]
function slider_callback(hObject, eventdata)
a = get(hObject, 'Value');
disp(a);

Best Answer

Related Solutions

MATLAB: Increasing slider value of a GUI

MATLAB: How to Change the Min property of slider

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