在 MATLAB 中使用连续滑块的值

Question

我有点被困在这里。我试图阅读和实现一些简单的连续滑块脚本（比如这个），但我一无所获。

我只想做的是，当我滑动滑块时，在我的绘图中使用连续滑块值。但是，我无法弄清楚如何提取滑块的值来执行此操作。

例如，制作一个连续滑块，然后使用它来改变矢量的振幅，比如说，当你连续滑动它时。怎么能做到这一点呢？

谢谢。

Answer 1

像这样的东西？

function sliderDemo
    f = figure(1);
    %// Some simple to plot function (with tuneable parameter)
    x = 0:0.1:2*pi;
    y = @(A) A*sin(x);
    %// Make initial plot
    A = 1;
    p = plot(x, y(A));
    axis tight
    axis([0 2*pi -10 10])
    %// re-position the axes to make room for the slider
    set(gca, 'position', [0.1 0.25 0.85 0.7]);
    %// initialize the slider
    h = uicontrol(...
        'parent'  , f,...        
        'units'   , 'normalized',...    %// so yo don't have to f*ck with pixels
        'style'   , 'slider',...        
        'position', [0.05 0.05 0.9 0.05],...
        'min'     , 1,...               %// Make the A between 1...
        'max'     , 10,...              %// and 10, with initial value
        'value'   , A,...               %// as set above.
        'callback', @sliderCallback);   %// This is called when using the arrows
                                        %// and/or when clicking the slider bar

    %// THE MAGIC INGREDIENT
    %// ===========================
    hLstn = handle.listener(h,'ActionEvent',@sliderCallback); %#ok<NASGU>
    %// (variable appears unused, but not assigning it to anything means that 
    %// the listener is stored in the 'ans' variable. If "one_answers" is overwritten, 
    %// the listener goes out of scope and is thus destroyed, and thus, it no 
    %// longer works.
    %// ===========================

    %// The slider's callback:
    %//    1) clears the old plot
    %//    2) computes new values using the (continuously) updated slider values
    %//    3) re-draw the plot and re-set the axes settings
    function sliderCallback(~,~)
        delete(p);
        p = plot(x, y(get(h,'value')));
        axis tight
        axis([0 2*pi -10 10])
    end
end

PS - 你找不到它并不奇怪 - 它没有记录在案。我从Yair Altman的网站上知道这一点。

Answer 2

从 Matlab 2014a 开始，您可以使用：

addlistener(h_slider,'ContinuousValueChange',@slider);

其中@slider是要定义的回调函数。工作整洁。

在回调中，您可以简单地使用：

slider_value=get(handle,'value');

（来源）

Answer 3

若要从滑块中提取值，请使用滑块手柄的get方法，如下所示，

sliderValue = get(hSlider,'Value')