How do I insert a variable text string in matlab plot?

Part of my code is

d_close = 3*(r1_eq + r2_eq)
figure(101);
h1 = plot(normalized_time, r1_us, 'b-', normalized_time, r2_us, 'k:');
set(h1,'linewidth',2);
txt = ['d = ', num2str(d_close)];
% t = text(0.0025, 17, txt);
t.FontSize = 24;
legend(['Bubble-1'], ['Bubble-2'])

and so on...

I wish to put sort of additional "third" legend for a plot that has two curves (r1_us and r2_us versus normalized time) only. So, I had to opt for string-method to put the additional information on the plot. But when I run the code, I get the error

Unable to perform assignment because dot indexing is not supported for variables of this type.

Error in bubble_mettin_solver (line 25)

t.FontSize = 24;

So how do I fix this? Please help. I wish that every time the plot shows up it has the information of updated d_close value.

By the way can I have a third legend in which there are only two curves? I know how to implement variable legend, but not the text.

[madhan ravi]

upload datas of r1_eq and r2_eq

[Vikash Pandey]

The actual code is this:

clc;
clear all;
%close all;
time_range = [0 0.6d-4];
r1_eq = 10d-6;
r2_eq = 10d-6;
f_s = 20000;
initial_conditions = [r1_eq 0.d0 r2_eq 0.d0];
[t, r] = ode45('bubble_mettin', time_range, initial_conditions);
r1_us=1000000*r(:,1);
r1dot=r(:,2);
r2_us=1000000*r(:,3);
r2dot=r(:,4);
max_radii_combined = (max(r2_us) + max (r1_us))/1d6
d_close = 3*(r1_eq + r2_eq)
d_far = 300*(r1_eq + r2_eq)
diff_close_safe_positive = d_close - max_radii_combined
diff_far_safe_positive = d_far - max_radii_combined
figure(101);
normalized_time = t./(1/f_s);
h1 = plot(normalized_time, r1_us, 'b-', normalized_time, r2_us, 'k:');
set(h1,'linewidth',2);
txt = ['d = ', num2str(d_close)];
% t = text(0.0025, 17, txt);
t.FontSize = 24;
legend(['Bubble-1'], ['Bubble-2'])
legend('Location','Northwest')
set(gca,'xscale','linear','FontSize',26)
set(gca,'yscale','linear','FontSize',26)
set(gca,'XMinorTick','on')
set(gca,'YMinorTick','on')
%xlim([0 1]);
%ylim([0 24]);
%axis 'auto x'
grid off
xlabel('Normalized time, $t/T_{s}$','interpreter','latex','FontSize',34);
ylabel('Radii, $R_{1,2 \mbox{ }} (\mu m)$','interpreter','latex','FontSize',34)
hold off

[madhan ravi]

bubble_mettin?

[Vikash Pandey]

I have partly fixed it myself using: But how do I latex the fonts and also how do I increase its size.

text(0.2, 21, sprintf('d = ', num2str(d_close)));
text.FontSize = 34;

text.Fontsize does not seem to work.

[Stephen23]

Get rid of these square breckets:

legend(['Bubble-1'], ['Bubble-2'])

They do nothing useful whatsoever:

https://www.mathworks.com/matlabcentral/answers/35676-why-not-use-square-brackets

[Vikash Pandey]

Agreed. removed but currently I am facing another issue.

Answer 1

[madhan ravi]

see https://www.mathworks.com/help/matlab/ref/texlabel.html

t=text(0.2, 21, ['d = ' num2str(d_close)]);
t.FontSize = 34;

Vikash pandey's solution:

txt = text(0.03, 21, ("$d =\mbox{ }$" + d_close*1d6 + "$\mu m$"),'Interpreter','latex');
txt.FontSize = 28;

[Vikash Pandey]

Tried:

txt = texlabel('d = ', d_close);
text(0.2,20,txt)

did not worked. The value of d is missing.

[madhan ravi]

txt = texlabel('d = ', d_close);

should be

txt = texlabel(['d = ', num2str(d_close)]);

[Vikash Pandey]

Thanks Madhan. Appreciated.

[madhan ravi]

Anytime :)

[Vikash Pandey]

Madhan, What if I wish to have mu m in latex (greek letters) after the value of d_close?

[Vikash Pandey]

I tried:

txt = text(0.05, 21, texlabel(['d = ' num2str(d_close) 'mu m']));

Did not worked.

[Vikash Pandey]

Update: I got it to work partly

    txt = text(0.05, 21, (['d = ' num2str(d_close), '\mu m']));
    txt.FontSize = 24;

But, "m" does not look like a mathematical character as it looks neat in latex. Here in Matlab it looks like just a regular alphabetic letter. I wish mu and m to appear as they appear from latex coding $\mu m$ in the respective pdf file.

[madhan ravi]

yes where were we? so you want to display mu and m?

[madhan ravi]

There you go!

a='\mu','Interpreter','latex'
txt = text(0.05, 21, ['d = ' num2str(d_close), a,'m']);
txt.FontSize = 24;

[Vikash Pandey]

tried, No change at all. Same as before. "m" looks like regular alphabet.

[madhan ravi]

by the way how does your variable m is in latex form in the(ylabel) picture below?

[Vikash Pandey]

So no remedy for latex letters in text string?

For the labels, I used this:

xlabel('Normalized time, $t/T_{s}$','interpreter','latex','FontSize',34);
ylabel('Radii, $R_{1,2 \mbox{ }} (\mu m)$','interpreter','latex','FontSize',34)

[madhan ravi]

Guess so ,did a lot of research but couldn't succeed though!

[Vikash Pandey]

It happens. It is okay, not a big deal so far. I was looking for that only for aesthetic purposes. By the way I have posted one more problem in case it interests you.

https://www.mathworks.com/matlabcentral/answers/429660-how-do-i-output-the-second-derivative-from-ode-solver-for-further-use

[Vikash Pandey]

FYI, I found an alternative way:

txt = text(0.03, 21.5,'$$d = 33 \mu m$$', 'interpreter','latex')
txt.FontSize = 28;

[madhan ravi]

cool but you dont get to use num2str do you?

[Vikash Pandey]

Nope, num2str makes it difficult to work. But I have to get 10 plots or so. I will do hard-coding as shown above to obtain relatively good plots. By the way, had a look at this: https://www.mathworks.com/matlabcentral/answers/429660-how-do-i-output-the-second-derivative-from-ode-solver-for-further-use

?

[Vikash Pandey]

Madhan. I found the solution to the problem from a user in Stackoverflow. The solution is:

txt = text(0.03, 21, ("$d =\mbox{ }$" + d_close*1d6 + "$\mu m$"),'Interpreter','latex');

txt.FontSize = 28;

[madhan ravi]

wow that's cool!

Answer 2

[Jan]

Start with omitting the clear all, because this is a waste of time only. The error message is clear: Your t is the output of ode45() and a double vector. Then you cannot define t.FontSize. In the line before, the t would have been re-defined, but it is commented:

% t = text(0.0025, 17, txt);

Either delete the "%" character there or better use a unique name for the variable:

TestH = text(0.0025, 17, txt);
TextH.FontSize = 24;

It is not clear, what a "third legend" is. There is one legend only and not even a second one. Do you want to get a third entry in this legend? This would be confusing, because readers expect the same number of lines as legend entries. Maybe an additional title helps: https://www.mathworks.com/matlabcentral/answers/324848-setting-a-title-for-a-legend

[Vikash Pandey]

Thanks for the advise. I corrected it. But still a minor issue remains. Please see above.

Answer 3

[Vikash Pandey]

Yes. you see the plot here, mu looks so different than m in the plot. I want them to be latex equally. By the way I have solved the bubble coupled ODE problem that I had posted yesterday. Hope you remember. :)