按下按钮时将刷过的数据保存到变量

Question

我试图在单击按钮时将刷过的数据保存到一个变量中。我已阅读 other questions 但找不到执行此操作的方法。

在脚本中，以下代码有效：

t=0:0.2:25;
x=sin(t);
n=plot(t,x,'s');
brush on
pause
brushedData = find(get(n,'BrushData'));

然而，调用函数selectBrush不起作用：

function selectBrush()
% Create data
t=0:0.2:25;
x=sin(t);

% Create figure with points
fig=figure();
n=plot(t,x,'s');
brush on;
addBP = uicontrol(1,'Style', 'pushbutton',...
        'String', 'Get selected points index',...
        'Position',[5, 5, 200, 30],...
        'Units','pixel',...
        'Callback',@()assignin('caller','selectedPoints',get(n,'BrushData')));

% ---> Now the user should select the points and click the button 'Get
% selected points index'
waitfor(fig)

% Display index of selected points once the figure is closed
disp(selectedPoints);
end

我变成的错误信息是

Error using selectBrush>@()assignin('caller','selectedPoints',get(n,'BrushData'))
Too many input arguments.

我试过其他方法，比如使用 eval('selectedPoints=,get(n,''BrushData'')') 作为回调函数，使用句柄或单独定义一个新的回调函数，但都没有成功。

我应该怎么做？

编辑 1

excaza 的方法似乎有效，但回调函数仅在我重新定义的变量的原始值上执行，而不是在更新后的值上执行。

用下面的代码，

function testcode()
% Create data
t = 0:0.2:25;
x = sin(t);

% Create figure with points
myfig = figure();
n = plot(t, x, 's');
brush on;
pointslist=[];
uicontrol('Parent', myfig, ...
          'Style', 'pushbutton',...
          'String', 'Get selected points index',...
          'Position', [5, 5, 200, 30],...
          'Units', 'pixels',...
          'Callback', {@mycallback, n, pointslist} ...
           );

% ---> Now the user should select the points and click the button 'Get
% selected points index'
waitfor(myfig)

% Display index of selected points once the figure is closed
disp(pointslist);
end

function mycallback(~, ~, mylineseries, pointslist)
% Ignore the first 2 function inputs: handle of invoking object & event
% data

assignin('caller', 'pointslist', [pointslist find(get(mylineseries,'BrushData'))])
end

如果我在关闭前多次按下按钮，我希望在按下按钮时保存点数，而不仅仅是最后一次按下按钮。

Answer 1

从the documentation开始，MATLAB的回调默认总是发送2个变量：

The handle of the object whose callback is executing. Use this handle within your callback function to refer to the callback object.

The event data structure, which can be empty for some callbacks or contain specific information that is described in the property description for that object.

所以这里发生的事情是 assignin 调用被传递的变量多于它可以处理的 2 个变量，这就是它抛出错误的原因（我建议在您的问题中包含错误消息）。

要立即解决问题，您可以使用文档中提到的元胞数组表示法来创建本地回调函数：

function testcode()
% Create data
t = 0:0.2:25;
x = sin(t);

% Create figure with points
myfig = figure();
n = plot(t, x, 's');
brush on;
uicontrol('Parent', myfig, ...
          'Style', 'pushbutton',...
          'String', 'Get selected points index',...
          'Position', [5, 5, 200, 30],...
          'Units', 'pixels',...
          'Callback', {@mycallback, n} ...
           );

% ---> Now the user should select the points and click the button 'Get
% selected points index'
waitfor(myfig)

% Display index of selected points once the figure is closed
disp(selectedPoints);
end

function mycallback(~, ~, mylineseries)
% Ignore the first 2 function inputs: handle of invoking object & event
% data

assignin('caller', 'selectedPoints', get(mylineseries,'BrushData'))
end

应该可以正常运行。另请注意适当的 assignin 语法，它在您的示例中不正确。

按下按钮时将刷过的数据保存到变量

Save brushed data to variable on button push

matlab

brush

matlab-gui