string to argument in legend

I am trying to generate the legend for N plots. Each plot uses latex code. For example, in the following picture there are 10 sets and I inserted legends for 4 sets. I did

it manually using

legend(strcat('$${\mathcal X}_',num2str(3), '$$'), strcat('$${\mathcal X}_',num2str(2), '$$'), strcat('$${\mathcal X}_',num2str(1), '$$'),strcat('$${\mathcal X}_',num2str(0), '$$'),'Interpreter','latex')

So I wanted to generate the argument of the legend as a string. I did

for i=0:Nint-1
legI = strcat("strcat('$${\mathcal X}_',num2str(",num2str(Nint-i),"), '$$')");
legII=strcat(legII,legI,',');
end
legII=strcat(legII,strcat("strcat('$${\mathcal X}_',num2str(",num2str(0),"), '$$')"));

where Nint=10 (the number of sets). This gives me

legII =

"strcat('$${\mathcal X}_',num2str(10), '$$'),strcat('$${\mathcal X}_',num2str(9), '$$'),strcat('$${\mathcal X}_',num2str(8), '$$'),strcat('$${\mathcal X}_',num2str(7), '$$'),strcat('$${\mathcal X}_',num2str(6), '$$'),strcat('$${\mathcal X}_',num2str(5), '$$'),strcat('$${\mathcal X}_',num2str(4), '$$'),strcat('$${\mathcal X}_',num2str(3), '$$'),strcat('$${\mathcal X}_',num2str(2), '$$'),strcat('$${\mathcal X}_',num2str(1), '$$'),strcat('$${\mathcal X}_',num2str(0), '$$')"

then I did

legend(convertStringsToChars(legII),'Interpreter','latex');

but it didn't interepret the latex nor give me the Nint=10 legends.

[the cyclist]

Here is why what you are doing doesn't work. Take the simplified case of only trying to make the legend with X0. The "manual" version is this code:

legend(strcat('$${\mathcal X}_',num2str(0), '$$'),'Interpreter','latex')

But your "automated" version evaluates to this:

legend('strcat('$${\mathcal X}_',num2str(0), '$$')','Interpreter','latex')

[Ivan Perez Avellaneda]

yes, you're right, but I don't know how to transform the first into the second one. I used the function eval(legII), but no success.

Answer 1

[Walter Roberson]

for i=0:Nint
  legI(i+1) = "$${\mathcal X}_" + Nint-i + "$$";
end

legend(legI)

[Ivan Perez Avellaneda]

thank you, it works perfect. Just needed to put

legend(legI,'Interpreter','latex')

and that's it.