How can I combine variables with LaTex strings in a plot annotation?

I have an integer variable, phi. I want to display "phi = myvariable" on the plot. I think it is not working because I am mixing interpretable strings with variables in an incorrect manner.

I've posted the code below, followed by the Warnings that are generated.

Thanks in advance for you help.

close
%Define functions        
x = -3.0:0.01:3.0;
f = x.^2;
g = 5*sin(x) + 5;

% Plot function f
figure;
plot(x, f, 'r-', 'LineWidth', 2);

%Annotate the plot to display phi = (var:phi)
annotation('textbox',[.63 .25 .1 .2],'String',['$\phi = $' num2str(phi)],'interpreter','latex','BackgroundColor','white')

Warning: Unable to interpret LaTeX string "$\phi" > In scribe.textbox.createTextBox>localGetStrSize at 568 In scribe.textbox.createTextBox>localResizeText at 456 In scribe.textbox.createTextBox>localChangePosition at 337 In scribe.scribeobject.createScribeObject>localUpdatePosition at 48 Warning: Unable to interpret LaTeX string "$\phi =" > In scribe.textbox.createTextBox>localGetStrSize at 568 In scribe.textbox.createTextBox>localResizeText at 456 In scribe.textbox.createTextBox>localChangePosition at 337 In scribe.scribeobject.createScribeObject>localUpdatePosition at 48 Warning: Unable to interpret LaTeX string "$0.453" > In scribe.textbox.createTextBox>localGetStrSize at 568 In scribe.textbox.createTextBox>localResizeText at 456 In scribe.textbox.createTextBox>localChangePosition at 337 In scribe.scribeobject.createScribeObject>localUpdatePosition at 48 Warning: Unable to interpret LaTeX string "$\phi =$0.453" > In scribe.textbox.createTextBox>localGetStrSize at 568 In scribe.textbox.createTextBox>localResizeText at 461 In scribe.textbox.createTextBox>localChangePosition at 337 In scribe.scribeobject.createScribeObject>localUpdatePosition at 48 Warning: Unable to interpret LaTeX string "$\phi" > In scribe.textbox.createTextBox>localGetStrSize at 568 In scribe.textbox.createTextBox>localResizeText at 456 In scribe.textbox.createTextBox>localChangePosition at 337 In scribe.scribeobject.createScribeObject>localUpdatePosition at 48 Warning: Unable to interpret LaTeX string "$\phi =" > In scribe.textbox.createTextBox>localGetStrSize at 568 In scribe.textbox.createTextBox>localResizeText at 456 In scribe.textbox.createTextBox>localChangePosition at 337 In scribe.scribeobject.createScribeObject>localUpdatePosition at 48 Warning: Unable to interpret LaTeX string "$0.453" > In scribe.textbox.createTextBox>localGetStrSize at 568 In scribe.textbox.createTextBox>localResizeText at 456 In scribe.textbox.createTextBox>localChangePosition at 337 In scribe.scribeobject.createScribeObject>localUpdatePosition at 48 Warning: Unable to interpret LaTeX string "$\phi =$0.453" > In scribe.textbox.createTextBox>localGetStrSize at 568 In scribe.textbox.createTextBox>localResizeText at 461 In scribe.textbox.createTextBox>localChangePosition at 337 In scribe.scribeobject.createScribeObject>localUpdatePosition at 48 Warning: Unable to interpret LaTeX string "$\phi =$0.453"

[Kye Taylor]

In your code, phi is not defined. I can run your code and get a label like you'd expect, if I add a line like phi = 2;

What is your output from

which phi

Answer 1

[Sathish Kumar]

Add a space after the second $ symbol in '$\phi=$'...... Actually no latex compiler can understand $\phi=$1234.... You have to form $\phi=$ 1234 for the latax compiler to understand.(The space between the second $ and the number is important.