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The layout of a LaTeX expression

Source: R/latex-tree.R
latex_tree.Rd

Returns what a formula is drawn from: one row per glyph, line, rectangle or run of text, with its position. Useful for checking alignment or building your own grobs.

Usage

latex_tree(
  tex,
  math_font = "",
  max_width = 0,
  tex_style = "",
  input_mode = c("mixed", "math", "document"),
  render_mode = c("typeface", "path"),
  gp = grid::gpar()
)

Arguments

tex

LaTeX, as a character string.

math_font

Math font: "lete" (Lete Sans Math, the default), "stix" (STIX Two Math), or one added with load_math_font(). See available_math_fonts().

max_width

Width in big points (1/72 inch) at which lines wrap. 0, the default, does not wrap.

tex_style

Force a TeX style: "display", "text", "script" or "scriptscript". "", the default, follows the delimiters. See Details.

input_mode

How tex is read:

  • "mixed" (default): text, with math between $...$ or \(...\). A newline starts a new line.

  • "math": everything is math; write text in \text{}.

  • "document": a LaTeX document body, with paragraphs, numbered headings and displayed equations. Use it with max_width.

render_mode

"typeface" (default) draws glyphs as text, which can be selected in PDF and SVG output. It needs a device such as ragg, svglite or grDevices::cairo_pdf(), and falls back to "path" on others, such as pdf(). "path" draws glyphs as outlines, which works on every device.

gp

Graphical parameters from grid::gpar(): col, fontfamily, fontsize, cex and lineheight. See Details.

Value

A list of class "latex_tree":

  • records: a data frame with one row per drawn element, with columns such as type, x, y, glyph, font_size, color and text.

  • bbox: width, height, depth and baseline, in big points.

  • tex: the input.

  • render_mode: the render mode used.

See also

latex_grob, latex_dims

Examples

# \donttest{
  tree <- latex_tree("\\frac{a}{b}")
  print(tree)
#> <latex_tree>
#>   tex:         \frac{a}{b}
#>   render_mode: typeface
#>   bbox:        width=7.00  height=25.00  depth=9.00  baseline=0.63 (bigpts)
#>   records:     3
#>     glyph      2
#>     line       1
  head(tree$records)
#>    type         x      y glyph font_size   color    x2     y2 width height rx
#> 1 glyph 0.1890002  7.196  3628        14 #000000    NA     NA    NA     NA NA
#> 2  line 0.0000000 10.596    NA        NA #000000 7.392 10.596    NA     NA NA
#> 3 glyph 0.0000000 25.796  3629        14 #000000    NA     NA    NA     NA NA
#>   ry  lwd text font_style rotation path codepoint
#> 1 NA   NA <NA>         NA        0 NULL        NA
#> 2 NA 1.32 <NA>         NA        0 NULL        NA
#> 3 NA   NA <NA>         NA        0 NULL        NA
#>                                                             font_file
#> 1 /home/runner/work/_temp/Library/gridmicrotex/fonts/LeteSansMath.otf
#> 2                                                                <NA>
#> 3 /home/runner/work/_temp/Library/gridmicrotex/fonts/LeteSansMath.otf
#>   font_family image_ref
#> 1        <NA>      <NA>
#> 2        <NA>      <NA>
#> 3        <NA>      <NA>
# }