Latex, sprintf and variable that changes

Hello everyone,

In the following MATLAB code snippet:

title(sprintf('\\textbf{Product of $\\phi$ with %0.2f delayed $\\phi(t-\\%%0.2f)$ and a = %0.1f}', k(j).*T , a(i)),'Interpreter','latex');

The objective is to create a plot title combining LaTeX formatting with the value of k(j)*T. However, there seems to be an issue with the rendering of the term $\phi(t-\%0.2f)$.

What could be causing the issue in the LaTeX expression, and how can it be fixed to combine LaTeX formatting with the value of k(j)*T effectively?

Thanks in advance

The complete code:

T=1/100;
over=100;
Ts=T/over;
A=4;
a=[0,0.5,1];
k=[0,1,2];
for i=1:length(a)
    [phi, t] = srrc_pulse(T,over,A,a(i));
    
    for j=1:length(k)
        figure(6*(i-1) + 2*(j-1) + 1);
        hold on;
        %subplot(2,1,1);
        plot(t,phi);
        
        hold on;
        
        title(sprintf('Pulses with a = %0.1f', a(i)));
        
        %subplot(2,1,2);
        
        tdelayed = t+(k(j).*T);
        plot(tdelayed,phi);
        legend('Original \phi',sprintf('delay %0.2f', k(j).*T));
        hold on;
        grid on;
        
        % Save the images
        filename_subplot = sprintf('subplotWithA=%d_K=%d.png', a(i), k(j));
        saveas(gcf, filename_subplot);

        phioriginal = [phi zeros(1,k(j)*T/Ts)];
        phidelayed = [zeros(1,k(j)*T/Ts)  phi];
        tmultiplication = [t(1):Ts:t(end)+k(j)*T];
        
        figure(6*(i-1) + 2*(j));
        plot(tmultiplication,phioriginal.*phidelayed);
        title(sprintf('\\textbf{Product of $\\phi$ with %0.2f delayed $\\phi(t-\\%%0.2f)$ and a = %0.1f}', k(j).*T , a(i)),'Interpreter','latex');
        grid on;

Answer 1

[Star Strider]

Your sprintf statement has fields for 3 variables, however you only provide 2.

Provide all 3 and it works —

i = 1;
j = 1;
a(i) = 42;
T = 273;
k(j) = 42^3/1E3;
something_else = rand*100;
title(sprintf('\\textbf{Product of $\\phi$ with %0.2f delayed $\\phi(t-%0.2f)$ and a = %0.1f}', k(j).*T ,  something_else, a(i)),'Interpreter','latex');

.

[Konstantinos]

The variables being used are:

k(j).*T , a(i)

However, I don't see the third variable. Also, when using your format, the result I am getting is:

Also my using your fomat the result that i am getting is:

[Star Strider]

You have only supplied two variables in your sprintf statement, however you provided field descriptors for three (in my corrected version of it).

I believe it is supposed to be something like this —

phi = rand;
i = 1;
j = 1;
a(i) = 42;
T = 273;
k(j) = randi(99);

figure
title(sprintf('\\textbf{Product of $\\phi$ with %0.2f delayed $\\phi(t-%0.2f)$ and a = %0.1f}', phi, k(j).*T , a(i)),'Interpreter','latex');

However I don’t know because I don’t know what you want to print in that statement. You need to provide one argument for each edit descriptor.

Note that this:

title(sprintf('\\textbf{Product of $\\phi$ with %0.2f delayed $\\phi(t-\\%%0.2f)$ and a = %0.1f}', k(j).*T , a(i)),'Interpreter','latex')

↑ ← '\\' REPEATED

‘escapes’ (because of the ‘\\’) that particular format descriptor and ‘%%’ prints a single % character so that it prints out as:

figure
title(sprintf('\\textbf{Product of $\\phi$ with %0.2f delayed $\\phi(t-\\%%0.2f)$ and a = %0.1f}', k(j).*T , a(i)),'Interpreter','latex');

which is exactly what you told it to do.

Note — My version prints differently (and likely correctly), and is probably what you want.

.

[Konstantinos]

I realize now that I was fixated on the variable 'something_else' and overlooked the fact that my string actually contains three variables. Thank you for your assistance, and I apologize for the misunderstanding.

[Star Strider]

As always, my pleasure!

No worries!

No apology necessary. (I probably should have stated initially what I stated in my previous Comment. Still early here.)