MATLAB：绘制线条颜色

这是因为x和y您以前绘制的是缩放器。为了情节线索，您将需要存储所有x和y你得到ginput的载体和绘制矢量：

[x,y,button] = ginput(1);
switch button
    case 1 % left mouse
        xs = [xs x];
        ys = [ys y];
        p = plot(xs,ys,'w-*');
        % more code to go
end

但是，如果在每次输入新点时都绘制xs和，则ys线会重叠。为避免这种情况，我们只绘制第一个点并更新p.XData和p.YData为新点：

if isempty(p)
    p = plot(x,y,'w-*');
else
    p.XData = xs;
    p.YData = ys;

完整代码：

figure
hold on
axis([0,100,0,100])
grid off
set(gcf,'color','k')
set(gca,'color','k')
axis square

xs = [];
ys = [];
p = [];

while 1
    [x,y,button] = ginput(1);
    switch button
        case 1 % left mouse
            xs = [xs x];
            ys = [ys y];
            if isempty(p)
                p = plot(x,y,'w-*');
            else
                p.XData = xs;
                p.YData = ys;
            end
        case {'q','Q'} % on keyboard
            break;
    end
end

结果：