How to include function in legend

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I tried all possibl string2functions of Matlab, but not getting quiete the result.
Here's my best try:
syms x
F = x^2; % Definied Function
g = matlabFunction(F);
% some random steps
x = -10:0.1:10;
f = g(x);
p1 = plot(x,f);
hold on
n = 20;
C = jet(n);
for k= 1:n
p2 = plot(x,f+2*k,'Color',C(k,:));
end
% Here comes the questionable part.
legend([p1,p2],{strcat('f = ',char(F)),sprintf('f at n = %0.f',n)},...
'Interpreter','latex','FontSize',20)
Basically I want the function that I definied to be automatically updated in legend. (Pretty handy if you change f multiple times). However in my attemp I get a warning:
String scalar or character vector must have valid interpreter syntax:
f:x^2
How can the function be acknowledged by the interpreter?

Accepted Answer

Star Strider
Star Strider on 3 Jun 2021
A sllightly different approach —
syms x
F = x^2; % Definied Function
g = matlabFunction(F);
% some random steps
x = -10:0.1:10;
f = g(x);
p1 = plot(x,f);
hold on
n = 20;
C = jet(n);
for k= 1:n
p2 = plot(x,f+2*k,'Color',C(k,:));
end
% Here comes the questionable part.
legend([p1,p2],{sprintf('$f = %s$',char(F)),sprintf('$f\\ at\\ n = %0.f$',n)},...
'Interpreter','latex','FontSize',20)
.
  2 Comments
Niklas Kurz
Niklas Kurz on 3 Jun 2021
I reckognized 'latex(F)' instead of 'char(F)' is just more accurate at displaying functions like But either way it is working now! Just the right tweeking.

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More Answers (1)

Joseph Cheng
Joseph Cheng on 3 Jun 2021
Edited: Joseph Cheng on 3 Jun 2021
do you need to use latex as just using the default tex? as latex uses $ for markup of symbols i don't know if it'll take the syms function very well without some edits. if you get rid of the interpreter setting and use the default one
syms x
F = x^2; % Definied Function
g = matlabFunction(F);
% some random steps
x = -10:0.1:10;
f = g(x);
p1 = plot(x,f);
hold on
n = 20;
C = jet(n);
for k= 1:n
p2 = plot(x,f+2*k,'Color',C(k,:));
end
% Here comes the questionable part.
legend([p1,p2],{strcat('f = ',char(F)),sprintf('f at n = %0.f',n)},...
'FontSize',20)
more info can be found here in another matlab tex vs latex answers sub
  1 Comment
Niklas Kurz
Niklas Kurz on 3 Jun 2021
Edited: Niklas Kurz on 3 Jun 2021
Well, latex just looks more beautiful in my eyes :$

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