MATLAB Answers

Legend does not match plot

44 views (last 30 days)
I used the following code to generate my plot (and I want it later to include in my LateX document):
clear all; close all; clc;
a1 = 1; a2 = 1; c1 = 2.0; c2 = 1.8; time = 0:0.1:300;
wave1 = a1 * sin(c1*time);
wave2 = a2 * sin(c2*time);
wave3 = wave1 + wave2;
y = hilbert(wave3);
env = abs(y);
bound = 0.1*cos(0.2*time-pi);
plot(time,wave3,'k',time,[-1;1]*env,'--k',time,bound,'-.r', 'Linewidth',1.2);
ylabel(' $\eta$ (m)');
xlabel(' Time (s)');
legend = legend({'Short waves','Wave group envelope','Bound long wave'});
set(legend, 'FontSize',20);
axis([15.7 110 -2.5 2.5]);
set(groot, 'defaultAxesTickLabelInterpreter','latex'); set(groot, 'defaultLegendInterpreter','latex');
The graph looks like:
Clearly, the 'bound long wave' legend does not match the color and line specification in the graph. As far as I know, it has something to do with scalar/vector but I cannot figure out where the error is.
How to proceed further?


Sign in to comment.

Accepted Answer

Walter Roberson
Walter Roberson on 22 Jun 2016
Inside the plot, time,[-1;1]*env generates two lines, for a total of 4 overall. But you only legend() for three lines. The fix is:
h = plot(time, wave3, 'k', time, [-1;1]*env, '--k', time, bound, '-.r', 'Linewidth', 1.2);
Lh = legend(h([1, 2, 4]), {'Short waves','Wave group envelope','Bound long wave'});
set(Lh, 'FontSize',20);


Sign in to comment.

More Answers (1)

Muhammad Usman  Saleem
Muhammad Usman Saleem on 22 Jun 2016
let's fix this bug in your code, replace with this
legend = legend('Short waves','Wave group envelope','Bound long wave');


André on 22 Jun 2016
Unfortunately, that does not make the difference. The legend is still not correct.
Guillaume on 22 Jun 2016
Indeed, there is absolutely no difference in passing the legend strings as a comma-separated list or as a cell array (or a char array)
Walter Roberson
Walter Roberson on 22 Jun 2016
Passing as a cell array can be used to pass in some legend strings that would otherwise be interpreted as options.

Sign in to comment.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by