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content.org

@@ -3134,6 +3134,162 @@ that is not strictly necessary anymore. You might want to setup a
 separate email account for this purpose altogether if you're not
 comfortable with having a (potentially buggy) python script mucking
 around in your emails.
+*** DONE Subfigures in RevTex                                       :LaTeX:
+CLOSED: [2025-02-15 Sat 19:32]
+:PROPERTIES:
+:EXPORT_FILE_NAME: subfigures-in-revtex
+:ID:       d036f9e0-a55d-41a6-a884-8c377b50caf4
+:END:
+
+I'm in the process of writing a paper (yay!). Merrily I
+add a formula here a plot there; but my supervisor zeroes in
+immediately on a two-panel figure with sub figures called "a" and "b"
+saying:
+#+begin_quote
+The sub figure labels go in the top-left corner. You've read papers
+before, haven't you?
+#+end_quote
+Having indeed read papers before, I must have neglected to pay proper
+attention to sub-figure labels -- an inexcusable blunder -- so this
+was news to me. Unwilling to fix the issues by monkeying around in
+inkscape, I turned to stack overflow. We have the pleasure to be using
+the [[https://www.ctan.org/tex-archive/macros/latex/contrib/revtex][RevTeX]] document class and annoyingly this class happens to be
+incompatible with both the [[https://ctan.org/pkg/subcaption?lang=en][subcaption]] package and the part of [[https://ctan.org/pkg/subfloat][subfloat]]
+that controls where the captions go. The aforementioned packages are
+"the way" to do sub figures and most other solutions I found involved
+monkeying around with minipages.
+
+So that's what I did; but I wanted to do properly so I'd be able to
+give the sub figures referenceable labels. I came up with a
+surprisingly short piece of hacked-together LaTeX package which we
+will now walk through. If you're impatient, you can just grab the [[/tex/poormanssubfig.sty][sty]]
+file and jump ahead to the usage example.
+
+We begin by declaring the package.
+#+begin_src latex :tangle static/tex/poormanssubfig.sty
+  \NeedsTeXFormat{LaTeX2e}
+  \ProvidesPackage{poormanssubfig}[2025/02/14 A subfigure environment
+    with working labels in the top-left corner that is compatible with revtex.]
+#+end_src
+Then, we create a new counter for the subfigures to be able to
+generate use labels to reference them.
+#+begin_src latex :tangle site/static/tex/poormanssubfig.sty
+    \newcounter{subfigure}
+#+end_src
+The ~multifig~ environment resets the
+subfigure counter[fn::Which could also have been accomplished by an
+argument to ~\newcounter~.], and redefines the ~\thesubfigure~ macro to
+display references to the subfigure as ~[Figure Number] ([figure
+sublabel])~. The environment temporarily increases the Figure counter
+so that ~\thefigure~ prints the right number.  The three commands at the
+top of the below snipped allow the user to overwrite the way the label
+is printed and formatted.
+#+begin_src latex :tangle site/static/tex/poormanssubfig.sty
+  \newcommand{\subfiglabelformat}[1]{\raggedright{#1}}
+  \newcommand{\subfiglabelstyle}[1]{\alph{#1}}
+  \newcommand{\subfiglabelsize}{\small}
+  \newenvironment{multifig}%
+  {\addtocounter{figure}{1}%
+    \setcounter{subfigure}{0}%
+    \renewcommand\thesubfigure{\thefigure~(\subfiglabelstyle{subfigure})}%
+  }
+  {\addtocounter{figure}{-1}}
+#+end_src
+
+This is the point where the real hackery begins. We define an internal
+variables ~\if@insubfig~ whose use will become clear later. The
+subfigure environment takes two arguments, the first one being the
+width of the subfigure and the second being an optional label string
+(it's also where you put ~\label{[label]}~). The environment then
+creates a minipage with the appropriate width and prints the label of
+the figure in the top-left corner.
+#+begin_src latex :tangle site/static/tex/poormanssubfig.sty
+  \makeatletter
+  \ExplSyntaxOn
+  \newif\if@insubfig
+  \NewDocumentEnvironment{subfigure}{mO{}}{%
+    \@insubfigtrue%
+    \refstepcounter{subfigure}%
+    \begin{minipage}{#1}%
+      \subfiglabelformat{{\subfiglabelsize (\subfiglabelstyle{subfigure})~#2}}%
+      }
+      {\end{minipage}%
+    \@insubfigfalse%
+  }
+  \ExplSyntaxOff
+#+end_src
+
+This final bit is truly horrendous. I wanted to be able to refer to
+the subfigures in the figure caption using their labels, but a
+standard ~\ref{[label]}~ would print the figure number, too. So I stole
+some code from the [[https://ctan.org/tex-archive/macros/latex/contrib/cleveref][cleveref]] package to redefine the ~\label~ macro to
+write a new label format (with the label name ~[youlabel]@multifig~) to
+the auxiliary (=.aux)= file upon compilation. LaTeX reads the auxiliary
+file on the second pass and evaluates the ~\newlabel{[label]}~ macros
+therein. These tell latex which text to print when we use the macro
+~\ref{[label]}~. In our case this is just the sufigure counter value,
+without the figure number. I define a new reference command ~\subref~ to expand ~\ref~ but
+append ~@multifig~ to its argument, so that the text we stored using
+~\newlabel~ is used. These extra labels will only be generated for
+subfigures thanks to ~\if@insubfig~.
+#+begin_src latex :tangle site/static/tex/poormanssubfig.sty
+  \let\multifig@old@label\label%
+  \def\label#1{%
+    \multifig@old@label{#1}%
+    \if@insubfig%
+      \@bsphack%
+      \protected@write\@auxout{}%
+      {\string\newlabel{#1@multifig}{{(\subfiglabelstyle{subfigure})}%
+          {\thepage}%
+          {\@currentlabelname}%
+          {\@currentHref}{}%
+        }}%
+      \@esphack%
+    \fi
+  }%
+  \def\subref#1{\ref{#1@multifig}}
+  \makeatother
+#+end_src
+
+With these details out of the way, let's get to the part that you
+actually wanted to read about[fn::Who are you dear reader? Shoot me an
+email!]: The package is used in a similar way to -- who'd have thought
+it -- the subfigure package, but puts your label it the top left
+corner -- where it ought to be! Just put the ~.sty~ file somewhere ~TeX~
+will find it. For global installation, you can put it in your
+~$TEXMFHOME/tex/latex~ folder. For usage with a specific project, you
+can dump it next to your ~.tex~ file. And now, behold the below usage example.
+#+begin_src latex
+\begin{figure*}
+  \begin{multifig}
+    \begin{subfigure}{\columnwidth}{\label{subfig:descriptive-label}Some
+        text label.}
+      \begin{center}
+        \includegraphics[width=.8\columnwidth]{example-image-a}
+      \end{center}
+    \end{subfigure}
+    \begin{subfigure}{\columnwidth}{\label{subfig:another-descriptive-label}Another
+        text label.}
+      \begin{center}
+        \includegraphics[width=.8\columnwidth]{example-image-b}
+      \end{center}
+    \end{subfigure}
+  \end{multifig}
+  \caption{\label{fig:beautiful-figures}As the discerning eye may have
+    spied, the figures \subref{subfig:descriptive-label} and
+    \subref{subfig:another-descriptive-label} have the potential to
+    rock the foundations of society.}
+\end{figure*}
+Total nonsense, but I couldn't think of anything better to demonstrate
+Figure \ref{subfig:descriptive-label} and \ref{subfig:another-descriptive-label}.
+
+This produces the below result...
+#+end_src
+[[attachment:screen:b4ea3f2a-f6a3-467d-a9ae-56bb5f0b9084.png]]
+... and references in the text look like
+[[attachment:screen:fef71aa0-4836-4777-8c42-1118c37c26b9.png]]
+
+Cheers!
 
 ** Uncategorized                                            :@Uncategorized:
 *** Neuseeland Restauration
@@ -3501,6 +3657,7 @@ und Mantelstromtriebwerke.
 :PROPERTIES:
 :EXPORT_FILE_NAME: tired-of-downloading-the-same-paper-over-and-over-clickable-pdf-links-in-the-natbib-revtex-bibiography-dot
 :END:
+
 ** Canada                                                   :@Canada:
 *** DONE Entscheidung
 CLOSED: [2022-08-28 Sun 17:53]
@@ -4962,10 +5119,6 @@ chaotisch.
 
 
 * Local Vars
-
-* Footnotes
-
-[fn:6]
 # Local Variables:
 # eval: (org-hugo-auto-export-mode)
 # org-download-image-dir: "./static/images"

shell.nix

@@ -1,4 +1,4 @@
 { pkgs ? import <nixpkgs> {} }:
   pkgs.mkShell {
-  nativeBuildInputs = with pkgs; [ hugo ];
+    nativeBuildInputs = with pkgs.buildPackages; [ hugo nodejs ];
 }

site/config.toml

@@ -51,3 +51,8 @@ baseURL = "https://protagon.space"
 
 [permalinks]
   posts = "/:year/:month/:title/"
+
+[markup]
+  [markup.goldmark]
+    [markup.goldmark.renderer]
+    unsafe = true

site/content/posts/subfigures-in-revtex.md

@@ -0,0 +1,170 @@
++++
+title = "Subfigures in RevTex"
+author = ["Valentin Boettcher"]
+date = 2025-02-15T19:32:00-05:00
+tags = ["LaTeX"]
+categories = ["Hacks"]
+draft = false
++++
+
+I'm in the process of writing a paper (yay!). Merrily I
+add a formula here a plot there; but my supervisor zeroes in
+immediately on a two-panel figure with sub figures called "a" and "b"
+saying:
+
+> The sub figure labels go in the top-left corner. You've read papers
+> before, haven't you?
+
+Having indeed read papers before, I must have neglected to pay proper
+attention to sub-figure labels -- an inexcusable blunder -- so this
+was news to me. Unwilling to fix the issues by monkeying around in
+inkscape, I turned to stack overflow. We have the pleasure to be using
+the [RevTeX](https://www.ctan.org/tex-archive/macros/latex/contrib/revtex) document class and annoyingly this class happens to be
+incompatible with both the [subcaption](https://ctan.org/pkg/subcaption?lang=en) package and the part of [subfloat](https://ctan.org/pkg/subfloat)
+that controls where the captions go. The aforementioned packages are
+"the way" to do sub figures and most other solutions I found involved
+monkeying around with minipages.
+
+So that's what I did; but I wanted to do properly so I'd be able to
+give the sub figures referenceable labels. I came up with a
+surprisingly short piece of hacked-together LaTeX package which we
+will now walk through. If you're impatient, you can just grab the [sty](/tex/poormanssubfig.sty)
+file and jump ahead to the usage example.
+
+We begin by declaring the package.
+
+```latex
+\NeedsTeXFormat{LaTeX2e}
+\ProvidesPackage{poormanssubfig}[2025/02/14 A subfigure environment
+  with working labels in the top-left corner that is compatible with revtex.]
+```
+
+Then, we create a new counter for the subfigures to be able to
+generate use labels to reference them.
+
+```latex
+\newcounter{subfigure}
+```
+
+The `multifig` environment resets the
+subfigure counter[^fn:1], and redefines the `\thesubfigure` macro to
+display references to the subfigure as `[Figure Number] ([figure
+sublabel])`. The environment temporarily increases the Figure counter
+so that `\thefigure` prints the right number.  The three commands at the
+top of the below snipped allow the user to overwrite the way the label
+is printed and formatted.
+
+```latex
+\newcommand{\subfiglabelformat}[1]{\raggedright{#1}}
+\newcommand{\subfiglabelstyle}[1]{\alph{#1}}
+\newcommand{\subfiglabelsize}{\small}
+\newenvironment{multifig}%
+{\addtocounter{figure}{1}%
+  \setcounter{subfigure}{0}%
+  \renewcommand\thesubfigure{\thefigure~(\subfiglabelstyle{subfigure})}%
+}
+{\addtocounter{figure}{-1}}
+```
+
+This is the point where the real hackery begins. We define an internal
+variables `\if@insubfig` whose use will become clear later. The
+subfigure environment takes two arguments, the first one being the
+width of the subfigure and the second being an optional label string
+(it's also where you put `\label{[label]}`). The environment then
+creates a minipage with the appropriate width and prints the label of
+the figure in the top-left corner.
+
+```latex
+\makeatletter
+\ExplSyntaxOn
+\newif\if@insubfig
+\NewDocumentEnvironment{subfigure}{mO{}}{%
+  \@insubfigtrue%
+  \refstepcounter{subfigure}%
+  \begin{minipage}{#1}%
+    \subfiglabelformat{{\subfiglabelsize (\subfiglabelstyle{subfigure})~#2}}%
+    }
+    {\end{minipage}%
+  \@insubfigfalse%
+}
+\ExplSyntaxOff
+```
+
+This final bit is truly horrendous. I wanted to be able to refer to
+the subfigures in the figure caption using their labels, but a
+standard `\ref{[label]}` would print the figure number, too. So I stole
+some code from the [cleveref](https://ctan.org/tex-archive/macros/latex/contrib/cleveref) package to redefine the `\label` macro to
+write a new label format (with the label name `[youlabel]@multifig`) to
+the auxiliary (`.aux)` file upon compilation. LaTeX reads the auxiliary
+file on the second pass and evaluates the `\newlabel{[label]}` macros
+therein. These tell latex which text to print when we use the macro
+`\ref{[label]}`. In our case this is just the sufigure counter value,
+without the figure number. I define a new reference command `\subref` to expand `\ref` but
+append `@multifig` to its argument, so that the text we stored using
+`\newlabel` is used. These extra labels will only be generated for
+subfigures thanks to `\if@insubfig`.
+
+```latex
+\let\multifig@old@label\label%
+\def\label#1{%
+  \multifig@old@label{#1}%
+  \if@insubfig%
+    \@bsphack%
+    \protected@write\@auxout{}%
+    {\string\newlabel{#1@multifig}{{(\subfiglabelstyle{subfigure})}%
+        {\thepage}%
+        {\@currentlabelname}%
+        {\@currentHref}{}%
+      }}%
+    \@esphack%
+  \fi
+}%
+\def\subref#1{\ref{#1@multifig}}
+\makeatother
+```
+
+With these details out of the way, let's get to the part that you
+actually wanted to read about[^fn:2]: The package is used in a similar way to -- who'd have thought
+it -- the subfigure package, but puts your label it the top left
+corner -- where it ought to be! Just put the `.sty` file somewhere `TeX`
+will find it. For global installation, you can put it in your
+`$TEXMFHOME/tex/latex` folder. For usage with a specific project, you
+can dump it next to your `.tex` file. And now, behold the below usage example.
+
+```latex
+\begin{figure*}
+  \begin{multifig}
+    \begin{subfigure}{\columnwidth}{\label{subfig:descriptive-label}Some
+        text label.}
+      \begin{center}
+        \includegraphics[width=.8\columnwidth]{example-image-a}
+      \end{center}
+    \end{subfigure}
+    \begin{subfigure}{\columnwidth}{\label{subfig:another-descriptive-label}Another
+        text label.}
+      \begin{center}
+        \includegraphics[width=.8\columnwidth]{example-image-b}
+      \end{center}
+    \end{subfigure}
+  \end{multifig}
+  \caption{\label{fig:beautiful-figures}As the discerning eye may have
+    spied, the figures \subref{subfig:descriptive-label} and
+    \subref{subfig:another-descriptive-label} have the potential to
+    rock the foundations of society.}
+\end{figure*}
+Total nonsense, but I couldn't think of anything better to demonstrate
+Figure \ref{subfig:descriptive-label} and \ref{subfig:another-descriptive-label}.
+
+This produces the below result...
+```
+
+![](/ox-hugo/screen:b4ea3f2a-f6a3-467d-a9ae-56bb5f0b9084.png)
+... and references in the text look like
+![](/ox-hugo/screen:fef71aa0-4836-4777-8c42-1118c37c26b9.png)
+
+Cheers!
+
+[^fn:1]: Which could also have been accomplished by an
+    argument to `\newcounter`.
+[^fn:2]: Who are you dear reader? Shoot me an
+    email!

site/static/tex/poormanssubfig.sty

@@ -0,0 +1,42 @@
+\newcounter{subfigure}
+
+\newcommand{\subfiglabelformat}[1]{\raggedright{#1}}
+\newcommand{\subfiglabelstyle}[1]{\alph{#1}}
+\newcommand{\subfiglabelsize}{\small}
+\newenvironment{multifig}%
+{\addtocounter{figure}{1}%
+  \setcounter{subfigure}{0}%
+  \renewcommand\thesubfigure{\thefigure~(\subfiglabelstyle{subfigure})}%
+}
+{\addtocounter{figure}{-1}}
+
+\makeatletter
+\ExplSyntaxOn
+\newif\if@insubfig
+\NewDocumentEnvironment{subfigure}{mO{}}{%
+  \@insubfigtrue%
+  \refstepcounter{subfigure}%
+  \begin{minipage}{#1}%
+    \subfiglabelformat{{\subfiglabelsize (\subfiglabelstyle{subfigure})~#2}}%
+    }
+    {\end{minipage}%
+  \@insubfigfalse%
+}
+\ExplSyntaxOff
+
+\let\multifig@old@label\label%
+\def\label#1{%
+  \multifig@old@label{#1}%
+  \if@insubfig%
+    \@bsphack%
+    \protected@write\@auxout{}%
+    {\string\newlabel{#1@multifig}{{(\subfiglabelstyle{subfigure})}%
+        {\thepage}%
+        {\@currentlabelname}%
+        {\@currentHref}{}%
+      }}%
+    \@esphack%
+  \fi
+}%
+\def\subref#1{\ref{#1@multifig}}
+\makeatother

static/tex/poormanssubfig.sty

@@ -0,0 +1,3 @@
+\NeedsTeXFormat{LaTeX2e}
+\ProvidesPackage{poormanssubfig}[2025/02/14 A subfigure environment
+  with working labels in the top-left corner that is compatible with revtex.]