Is it possible to output expressions using Latex?

Hi, I have to solve some expressions but I want my results to be easily understood, so I am looking for a method in order to print or to show my outputs in a Latex form just like the "Equation" does in the "Live Scripts".

For example: I have to output an expression like this:

m*double_dot_x+J*double_dot_theta

The method I use now is:

ddx = double_dot_x;

ddtheta = double_dot_theta;

so it is like: m*ddx+J*ddtheta which is better but still not very "user friendly"

I would like to have something like "\ddot x" and "\ddot \theta"

The problem now is that in a very long expression with terms like those it is very simple to confuse a dx with a ddx for istance, which is a big mistake in this case so the Latex rapresentation would be much better.

So the question is again is there a way to output in this way?

Answer 1

[Star Strider]

If you have the Symbolic Math Toolbox, it will format expressions into LaTeX for you.

Example —

syms J m theta(t) x(t) t 

Expr = m*diff(x,2) + J*diff(theta,2);

LaTeX_Expr = latex(Expr)

LaTeX_Expr =
    'm\,\frac{\partial ^2}{\partial t^2} x\left(t\right)+J\,\frac{\partial ^2}{\partial t^2} \mathrm{theta}\left(t\right)'

To use them in title and other objects in MATLAB, you then have to surround them sith '$' or '$$':

title(['$$' LaTeX_Expr '$$'], 'Interpreter','latex')

[Nicu Morosan]

Ok, that seems to be what I am looking for, but I tried your code and it shows me a figure but with nothing on it

[Star Strider]

I did not include all the code I used to test the title call, since it did not seem relevant at the time.

Here is the rest of it:

x = rand(1,100);
y = rand(1,100);

figure(1)
scatter(x, y)
grid

syms J m theta(t) x(t) t 

Expr = m*diff(x,2) + J*diff(theta,2);

LaTeX_Expr = latex(Expr)

title(['$$' LaTeX_Expr '$$'], 'Interpreter','latex')

[Walter Roberson]

No, you need to call latex() yourself -- unless you are willing to edit the source symbolic/symbolic/@sym/display.m

Answer 2

[Steven Lord]

One option is to use a Live Script.

A second option involves using publish on your script or function and specify LaTeX as the 'format'.

If you're working with symbolic expressions you could use the latex function or the pretty function instead.

[Nicu Morosan]

I tried the Live Script, but the problem is that if you want a nice output, you have to insert the equation manually, but I want the result of all my calculations to be displayed automatically in Latex format. Latex unfortunatelly do no add the double dot on "x" if my result is like: ddx. The function pretty is a quite good alternative but it is not so clean, I already tried it :)