Subtract integer from floats and integers in \foreach loop - (pdf)Latex [Overleaf]

Question

I would like to subtract the integer 1 from the names of the files I have included in the for loop. Although this works for the integer values, the float doesn't decrease by one, but rather shows '63.1-1' for example. Would like help with this. Thank you!

I have tried using the math operator, using '\the\numexpr\x-1\relax'. The former didn't work for both floats and integers, while the later only worked for integers. You can find my code here:

\usepackage{graphicx, pgffor}

\foreach \x in {59, 60.1, 60.2, 62, 63.1, 63.2, 65, 66.1, 66.2, 67.1}{%
  \parbox{.4\textwidth}{\centering\includegraphics[width=\linewidth]{Figures/Graphs/Picture\x.png}\par \tiny Slide \the\numexpr\x-1\relax}\space%
}%

This might help: https://tex.stackexchange.com/questions/83731/how-to-evaluate-an-expression-before-printing-it — giusti, Jan 19 '23 at 20:58
@Hithesh Please include a [mre] including all packages etc. to compile your code — samcarter_is_at_topanswers.xyz, Jan 19 '23 at 20:59
@giusti this partially works but the integers now appear are floats (for example 58.0). Anyway to represent whole numbers as whole and not floats? Thanks in advance. — Hithesh, Jan 19 '23 at 21:41
I don't know, but this should help: https://tex.stackexchange.com/questions/32341/print-integer-without-fraction-part — giusti, Jan 19 '23 at 21:46

Celdor · Accepted Answer · 2023-01-20T16:22:29.253

Tikz or PGF does not evaluate numbers. Use evaluate as directive inside foreach with an additional variable. As to the \numexpr, it only works with integers.

\documentclass[12pt, a4paper]{article}
\usepackage{graphicx,pgffor}
\begin{document}
\noindent
\foreach \x [evaluate=\x as \y using {\x-1}]
    in {59, 60.1, 60.2, 62, 63.1, 63.2, 65, 66.1, 66.2, 67.1}{%
    \parbox{.4\textwidth}{%
        \centering
        \includegraphics[width=\linewidth]{example-image-duck}
        \par\small Slide \y}\space}
\end{document}

Edit. You can also work out the number using \pgfmathparse{}\pgfmathresult combo. The last line would be:

\par\small Slide \pgfmathparse{\x-1}\pgfmathresult}\space}

Subtract integer from floats and integers in \foreach loop - (pdf)Latex [Overleaf]

1 Answers1