Legend function does not work in R2019b

The following lines of code is just a simple use of legend function.

x = linspace(0,2*pi,360);
y = sin(x);
plot(x,y);
legend('sin(x)');

But the result I get in my computer is incomplete: the legend dose not show the line of the curve.

I run the code in mac and it doesn't have this issue. My system is windows 10 and the version of matlab is R2019b. I don't know what causes this problem and hope someone can help me figure it out.

Answer 1

[Star Strider]

It was pointed out recently in another Question with a problem similar to yours that:

opengl software

is likely the appropriate solution.

EDIT — (1 Sep 2020 at 12:22)

This turned out to be a problem with certain AMD graphics drivers. The current versions (fixed a few months ago) correct the problem that caused this. Updating the AMD graphics driver solves it.

EDIT — (2 Oct 2020 at 19:33)

See this Comment for further details.

[Hangjun He]

Thank you! It works. I use the command

opengl('save','software')

and now I get my desired result. Thank you for your help!

[Star Strider]

As always, my pleasure!

Answer 2

[Sulaymon Eshkabilov]

Hi,

Your code is running ok in Win 10 and MATLAB 2019b. You should close all figure windows, run clear all command or/and if possible restart your MATLAB. Then you should get the anticipated outcome from your code.

Just an additional step to test your MATLAB is to run this slightly edited code of yours:

x = linspace(0,2*pi,360);
y = sin(x);
plot(x,y, 'b-o');
legend('sin(x)');

Good luck.

[Hangjun He]

Hi,

Things didn't go smooth after I restart my MATLAB. But I solved this problem by this command

opengl('save','software')

Thank you anyway.

[RANJAN HALDER]

Thank You sir, opengl command didn't work for me by clearing all (excecuting clear all command), legend function is perfectly working for me.