I want to write a (math-heavy) personal diary in LaTex. I thought of each entry be a section; something like

\section{Some title, 2017-01-13}

In addition, and as in a blog, I would like to categorize my entries (via a special command?) and would like LaTex to generate a ToC for every category.

E.g.

Category Calculus

Calculus, 2016-09-01 Derivatives, 2016-10-01

Category Algebra

Vectors, 2016-12-02 Matrices, 2017-01-02

How can I achieve this? I'm also grateful for pointers to similar projects (templates).

• We already have a similar question on the site: Using LaTeX to keep a diary. Perhaps that is of some help. – Alan Munn Jan 15 '17 at 19:53
• Thanks for the pointer; however, the linked thread does not solve the issue with creating a ToC for every category... – ClemensFMN Jan 17 '17 at 9:04

A proposition, with some slightly redefined \section command, getting an 2nd optional argument at the end, meant for the category -- the default value for this optional argument is Calculus here.

The ToC is generated as a separated index, which has the advantage of sorting with makeindex.

Please note that there are no fancy decorations here for the section title etc.

\documentclass{article}

\usepackage[margin=1in]{geometry}
\usepackage{xcolor}
\usepackage{xparse}
\usepackage{imakeidx}

\usepackage{hyperref}

\makeindex[name=cat,title={Categories}]

\let\sectionorig\section

\AtBeginDocument{%
\RenewDocumentCommand{\section}{s+o+m+O{Calculus}}{%
\clearpage%
\IfBooleanTF{#1}{%
\sectionorig*{#3}
}{%
\def\sectitle{#3}
\IfValueT{#2}{%
\def\sectitle{#2}
}%
\sectionorig[\sectitle]{#3}%
}%
\index[cat]{{\large\textbf{Category #4}\vskip0.5\baselineskip}!#3}%
}%
}

\begin{document}

\section{Vector algebra, \today}[Linear Algebra]

\section{Calculus, 2017-01-14}

\section{Derivatives, 2017-01-13}

\section{Tangents, 2017-01-5}

\section{Matrices, 2016-12-31}[Linear Algebra]

\printindex[cat]

\end{document}
`

• Would it be possible to index an entry under more than one category? For example, a blog post indexed under both Differential Equations and Matrix Algebra? – Bryan M-H Aug 27 '18 at 17:44