Add tex helpers

NAMESPACE

@@ -3,7 +3,9 @@
 export("%>%")
 export(cite_loaded_pkgs)
 export(make_pkg_bib)
+export(mattex)
 export(pkg_export)
+export(render_tex_files)
 export(rs_daily)
 export(rs_preview)
 export(rs_version)

R/tex-helpers.R

@@ -0,0 +1,65 @@
+#' Render a bunch of small .tex files
+#'
+#' Use case: A bunch of stuff done in LaTeXiT, resulting in some helper calculations
+#' or derivations contained in tex files. These are then rendered to PDF using `tex_fun`, per
+#' default [tinytex::xelatex], and then optionally converted to `png` using the system `convert`
+#' tool via imagemagick.
+#' @param path Folder where `.tex` files are.
+#' @param cleanup `TRUE`: Whether to cleanup auxilliary files (e.g. `.aux`, `.log`, ...)
+#' @param tex_fun Which function to use, default ist [tinytex::xelatex].
+#' @param to_png `TRUE`: Whether to use `convert` to convert PDF to png.
+#'
+#' @return Nothing
+#' @export
+#'
+#' @examples
+#' \dontrun{
+#' render_tex_files("formulas")
+#' }
+render_tex_files <- function(path, cleanup = TRUE, tex_fun = tinytex::xelatex, to_png = TRUE) {
+  tex_files <- list.files(path, pattern = ".tex$", full.names = TRUE, recursive = TRUE)
+  lapply(tex_files, tex_fun)
+
+  # Cleanup
+  if (cleanup) {
+    garbage <- list.files(path, pattern = ".aux$|.fls$|.synctex.gz$|.xdv$|.log$", full.names = TRUE)
+    file.remove(garbage)
+  }
+
+  # Convert to png?
+  if (to_png) {
+    f_pdfs <- shQuote(list.files(path, pattern = ".pdf$", full.names = TRUE, recursive = TRUE))
+
+    for (pdf in f_pdfs) {
+      f_png <- sub("\\.pdf", ".png", pdf)
+      command <- paste("convert -density 300 -flatten -colorspace RGB", pdf, f_png)
+      cat(command, "\n")
+      system(command)
+    }
+  }
+}
+
+#' Print a matrix for LaTeX.
+#'
+#' @param mat A [matrix].
+#' @param type `[character(1): "pmatrix"]`: Matrix environment to use, e.g. `bmatrix` for `[]`-enclosed
+#'  (brackets) or `pmatrix` for `()` (parentheses).
+#' @param round `[integer(1): 3]`
+#'
+#' @return Nothing, output is `cat`ed.
+#' @export
+#'
+#' @examples
+#' mat <- matrix(1:9, ncol = 3)
+#' mattex(mat)
+mattex <- function(mat, type = "pmatrix", round = 3) {
+  mat <- round(mat, round)
+  rows <- seq_len(nrow(mat))
+  spaced_rows <- sapply(rows, function(row) {
+    row <- mat[row, ]
+    paste(row, collapse = " & ")
+  })
+  matrix_rows <- paste(spaced_rows, collapse = " \\\\ \n ")
+
+  cat(paste0("\\[\\begin{", type, "}\n", matrix_rows, "\n\\end{", type, "}\\]"))
+}

inst/rmarkdown/templates/uebungsblatt/resources/template.tex

@@ -38,7 +38,13 @@
 \usepackage{amssymb,amsmath}
 % Note: mathspec loads fontspec anyway and things complain if fontspec is loaded before mathspec
 %\usepackage{mathspec}
-\usepackage{unicode-math}
+
+% unicode-math seems to be the preferred superset of mathspec (and fontspec?)
+% ISO means bold math is set italics, =TeX would make bold math upright
+\usepackage[bold-style=ISO]{unicode-math}
+% To make regular \boldsymbol be like \symbf (bold greek letters etc.)
+% this makes e.g. bold beta work in both PDF and mathjax (in HTML output)
+\renewcommand{\boldsymbol}[1]{\symbf{#1}}
 \defaultfontfeatures{Ligatures=TeX}%,Scale=MatchLowercase}
 
 % Useing the (sets) makes math non-italics for some reason?
@@ -240,6 +246,7 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %%% The actual document     %%%
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\allowdisplaybreaks
 \begin{document}
 
 $for(include-before)$