如何在不打印变量的情况下在 Matlab 循环中监视变量？

Question

我是运行一个循环，在循环中计算变量。能够查看这些变量的当前值将很有用。打印它们没有用，因为循环的其他部分正在打印大量文本。此外，在 Workspace 选项卡上，直到循环结束才会显示值。

有没有办法监控这些变量，f.i。通过将它们打印成 window?

Answer 1

您可以使用 text 对象创建图形并根据所需变量更新其 'string' 属性：

h = text(.5, .5, ''); %// create text object
for n = 1:1000
    v = n^2; %// loop computations here. Variable `v` is to be displayed
    set(h, 'string', ['Value: ' num2str(v)]);
    drawnow %// you may need this for immediate updating
end

为了提高速度，您可以每 S 次迭代只更新一次：

h = text(.5, .5, ''); %// create text object
S = 10; %// update period
for n = 1:1000
    v = n^2; %// loop computations here. Variable `v` is to be displayed
    if ~mod(n,S) %// update only at iterations S, 2*S, 3*S, ...
        set(h, 'string', ['Value: ' num2str(v)]);
        drawnow %// you may need this for immediate updating
    end
end

或使用 drawnow('limitrate') 如@Edric 所述：

h = text(.5, .5, ''); %// create text object
for n = 1:1000
    v = n^2; %// loop computations here. Variable `v` is to be displayed
    set(h, 'string', ['Value: ' num2str(v)]);
    drawnow('limitrate')
end

如何在不打印变量的情况下在 Matlab 循环中监视变量？

How can you monitor a variable during a Matlab loop without printing it?

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loops