MATLAB中忽略特定图例

在MATLAB画图中，有时需要忽略某些legend，有几种方法可以实现：

1. 在画不需要图例的线条时添加'HandleVisibility','off'

x = linspace(0,pi);
y1 = cos(x);
plot(x,y1);

hold on
y2 = cos(2*x);
plot(x,y2,'HandleVisibility','off');

y3 = cos(3*x);
plot(x,y3);
hold off
legend('First','Third')

2. 在legend函数中添加subset，例如

x = linspace(0,pi);
y1 = cos(x);
p1 = plot(x,y1);

hold on
y2 = cos(2*x);
p2 = plot(x,y2);

y3 = cos(3*x);
p3 = plot(x,y3);
hold off

legend([p1 p3],{'First','Third'})

两者效果相同