I want the xlabel of my Matlab figure to read v / Uinf, where the v has an overbar, and the inf is a symbol in subscript.
The line:
xlabel('$\bar{v}$','interpreter','latex')
creates the v overbar, and:
xlabel('U_\infty')
creates the U subscript infinity, but when I try to put them together, Matlab says 'String must have valid interpreter syntax'. It seems setting the interpreter to latex means the U_\infty command doesn't work any more.
Is there a way of writing U_infty that is compatible with latex or another way of writing the two together?
Thanks in advance,
Holly
In LaTeX, U_\infty works only in math mode, so you have to write $U_\infty$ instead.
Related
I would write my xlabel with Latec character so I used this code
x = -10:0.1:10;
y = [sin(x); cos(x)];
plot(x,y)
xlabel('$\mathbb{x}$','Interpreter','latex')
but I have this warning message
Warning: Error updating Text.
String scalar or character vector must have valid interpreter syntax:
$\mathbb{x}$
and the xlabel appear like this
https://i.stack.imgur.com/NCI4n.png
please how I can fix this problem.
The problem with your example is the mathbb command, which is not in base Latex. To show this, replace the \mathbb with, e.g., \mathrm. This will work.
I've never seen an example of adding Latex packages into the Matlab environment. (Update below)
You can have a look at this question, which includes a very aggressive potential way to add the package you need. But it's not clear to me if the solution proposed is actually functional.
How do you use the LaTeX blackboard font in MATLAB?
I'd like to create a single symbol which is contains a delta "∆" and a t.
For visualisation purposes i use Matlab Live Script.
Combining several latin letters is easy done by:
sym('dt')
But these either result in an exception or don't do a conversion:
sym('Delta t')
sym('Deltat')
The workaround to multiply two symbols does not work in all cases:
sym('Delta')*sym('t')
(sym('Delta')*sym('t'))^2
However, if i square the symbol, i'd like to have this behavior:
sym('dt')^2
But it should contain the delta symbol:
Is this what you want?
title('\Deltat')
If you want, you can also do
title('\Deltat^{2}')
The answer is no, you cant use non-ASCII for variables in MATLAB. This means no \Delta, no \epsilon, or any other non-standard chars.
You can generate the LaTeX representation of the results, and then print them either in text in MATLAB or in your favourite LaTeX editor with the function latex
In MatLab (R2015a), I want to style the title of my plots using latex.
This is working fine for some functions, but not if there's a power in the equation.
The below code works, and shows a formatted title to the right, and an unformatted title to the left.
It shows the warning:
Warning: Error updating Text.
String must have valid interpreter syntax: y = x^2
syms x y
eq = y == x^2;
subplot(1,2,1)
ezplot(eq)
title(latex(eq),'interpreter','latex')
eq = y == x+2;
subplot(1,2,2)
ezplot(eq)
title(latex(eq),'interpreter','latex')
EDIT:
I just found out I can get it to work by appending $ on both sides. But it seems weird that I would have to do this.
So this works:
title(strcat('$',latex(eq),'$'),'interpreter','latex')
Solution
The problem can be solved easily by adding $-signs before and after the generated LaTeX-expression. So you can change your «title-lines» to:
title(['$',latex(eq),'$'],'interpreter','latex')
An alternative is to use strcat as proposed in your question.
Explanation
Since you basically answered the question yourself already, I'm going to explain why it happened. Hopefully after reading this, it's no longer 'weird' behaviour. If you choose to use the LaTeX-interpreter in Matlab, you really get a LaTeX-interpreter. This means that the provided string must be valid LaTeX-syntax.
Using ^ outside a math-environment is considered invalid syntax because it is a reserved character in LaTeX. Some interpreters automatically add the $ before and after in this case, but throw a warning at the same time.
The output of the latex-function in Matlab is provided without the $-signs. This way you can combine outputs and concatenate if needed without creating a mess with $-signs.
To change to the math-environment in LaTeX you can use the already mentioned shortcut $...$. An alternative way is to use \begin{math} your_equation \end{math}. It produces the same result for your equations and can be used here for demonstration purposes. The following line would do the same job, but is a bit longer to write:
title(['\begin{math}',latex(eq),'\end{math}'],'interpreter','latex')
Now, the reason why only one of your equations is displayed correctly, lies in the invalid character ^ in y = x^2. Matlab then chooses interpreter none and therefore displays the string unformatted. The +-sign in y = x + 2 is valid outside a math-environment, so it gets displayed correctly (but is not interpreted in a math-environment).
I am trying to plot with Matlab. In particular, I try with numerous online source but none of them work.
Here is my problem, I am trying to plot the expression: y=2*(x-1)/(x-4)Kb/L, and I am interested in the range of x between 0 and 1.
K=40;
b=20;
L=0.5;
x=linspace(0,1,1000);
y=2*(x-1)/(x-4)*K*b/L;
but it returns:
y=275.01
I know linspace isn't the proper way to plot. How can I plot this function? I want to keep the K,b,L declaration because I might change them latter.
y=2*(x-1)./(x-4)*K*b/L; you should use ./ replace /
Like hzy199411 said, you should use the "." operation.
I would suggest that you type "help ." at a MATLAB command prompt. MATLAB will respond with a large index of results but look for the section on "Arithmetic Operators".
You may also try the command "doc arith" but I think the "help ." is more helpful because at least in MATLAB 2013 it verbosely lists more "dot" operators.
In short several arithmetic operators prefixed with '.' ("Dot") are "Element-by-Element" operations and as such they operate on each index of the array/matrix.
For example if you had an array s=1:20 and you performed the operation s/s you would get ans = 1, where as if you did s./s you would get an array of 1's with the same length as 's'.
I guess that you are a new matlab user :). The program is in general ok, but you should think of some things. First,
linspace is not a plotting function. The function is useful though. With your syntax it creates a vector of length 1000 with range [0,1]. For plotting, type:
plot(x,y);
Linecolor and style can be set as
plot(x,y,'r-.');
For predefined colors (here 'r-.' means a red dotted line). There are also some additional properties that can be found be checking the online help of plot.
Also as the others say, if you want to operate on each element in the vector, use ./. The / is a matrix operator.
Not that significant, but annoying to no end. Why does matlab has no small phi (\varphi) symbol ? It has pretty much all other symbols LaTeX offers, but not this one. Why ?
I may be wrong of course, in which case would be delighted if someone could prove me wrong...
The default interpreter is TeX actually, not LaTeX, which is why you're having this problem. You can use LaTeX as the interpreter for a given part doing something like this:
plot(1);
hl = legend('$$\varphi$$');
set(hl,'Interpreter','latex')
or you can set LaTeX as your default interpretor using
set(0,'DefaultTextInterpreter', 'latex');
which can be put in your startup.m file if you like.
Matlab uses TeX as default. Often, it is possible to switch to LaTeX, but in some cases (dialog boxes), this is impossible.
%# here's an example with all three phis
plot(rand(3))
yh = get(gca,'YLabel');
set(yh,'Interpreter','latex','string','$\varphi$ $\phi$ $\Phi$')