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How to display a percent sign (%) using latex and sprintf

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I am somewhat new to using latex for plot labels in MATLAB, and am having difficulty getting a percent sign to display using the combination of sprintf and latex. According to documentation for sprintf, the command for a percent sign would be this:
sprintf('New percent OS = $%.2f$ %%',percentOS)
However, this gives an error for the variable insertion portion of text,
I have also tried using the latex syntax for a percent sign, which would be:
sprintf('New percent OS = $%.2f$ $\%$',percentOS)
This gave a different error, but nonetheless did not work.
It seems that latex and sprintf having their own unique syntax is causing problems, but I am unsure what a solution would be.

Accepted Answer

Steven Lord
Steven Lord on 1 Apr 2021
percentOS = 23.45;
S = sprintf('New percent OS = $%.2f$ %%',percentOS)
S = 'New percent OS = $23.45$ %'
However, this gives an error for the variable insertion portion of text,
What is the full and exact text of the error message you received (all the text displayed in red)? As you can see from the code segment above, it does work at least in this simple case. If you have a more complicated example that throws the error please show it.
I have also tried using the latex syntax for a percent sign, which would be:
S2 = sprintf('New percent OS = $%.2f$ $\%$',percentOS)
Warning: Escaped character '\%' is not valid. See 'doc sprintf' for supported special characters.
S2 = 'New percent OS = $23.45$ $'
This gave a different error, but nonetheless did not work.
So as you can see this issues a warning but does not throw an error. Ah, I think I might know what's going on. Is the following the warning/error that you are asking about?
text(0.5, 0.5, S, 'Interpreter', 'LaTeX')
Warning: Error updating Text.

String scalar or character vector must have valid interpreter syntax:
New percent OS = $23.45$
If so:
figure
percentOS = 23.45;
S3 = sprintf('New percent OS = $%.2f$ \\%%',percentOS)
S3 = 'New percent OS = $23.45$ \%'
text(0.5, 0.5, S3, 'Interpreter', 'LaTeX')
The \\ in the format used to create S3 transforms into a \ in S3 itself just like the %% puts a % in the char array. The LaTeX interpreter interprets the \% as a percent sign. You could achieve the same result with string operations on S if you can't change the format.
S4 = replace(S, '%', '\%')
S4 = 'New percent OS = $23.45$ \%'
isequal(S3, S4)
ans = logical
1
  1 Comment
Ryan McLaughlin
Ryan McLaughlin on 1 Apr 2021
Yes, I should have originally included the text command as a part of my issue, but I was not aware this could be a part of the problem. Thanks for the help!

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More Answers (2)


Meg Noah
Meg Noah on 1 Apr 2021
% not using latex
loveMetric = 99.99;
fprintf(2,'I love matlab: %0.8f %%\n', loveMetric);

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