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Inspect the parsed layout of a LaTeX expression

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

Returns the raw draw-record table produced by MicroTeX's layout pass together with the bounding-box metadata. Useful for debugging alignment issues, building custom grobs on top of the layout, or counting glyphs/paths/rules in a formula.

Usage

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

Arguments

tex

Character string of LaTeX math code.

math_font

Name of the math font to use (e.g., "stix"). Use "" (default) for Lete Sans Math, which pairs with R's default sans-serif text font. See available_math_fonts for loaded fonts.

max_width

Numeric maximum width in big points for automatic line wrapping. Use 0 (default) for no wrapping.

tex_style

Character: TeX style override. One of "" (default; let the parser decide), "display", "text", "script", or "scriptscript". See latex_grob for the semantics of each value.

render_mode

Character string: "typeface" (default) renders glyphs as native text using the math font, producing selectable/accessible text in PDF and SVG output. Requires the math font to be installed on the system. Falls back to path mode automatically on devices that do not support font embedding (e.g., the base pdf() device). "path" renders math symbols as filled vector paths (works on all devices but text is not selectable in PDF/SVG). For PDF output with embedded/selectable text, prefer cairo_pdf.

gp

Graphical parameters (see gpar). Common entries: col (formula foreground), fontfamily / fontface (text font), fontsize / cex (formula size), and lineheight (multi-line spacing). See latex_grob for how each of these flows through MicroTeX.

Value

A list with class "latex_tree" containing:

records

Data frame of draw records (one row per glyph, path, line, rect, or text block). Columns include type, x, y, glyph, font_size, color, text, codepoint, font_file.

bbox

Named numeric vector with width, height, depth, baseline (all in big points).

tex

The (macro-expanded) input string.

render_mode

Rendering mode used for the layout.

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 ry
#> 1 glyph 0.175  7.224  2701        14 #000000    NA     NA    NA     NA NA NA
#> 2  line 0.000 10.624    NA        NA #000000 7.392 10.624    NA     NA NA NA
#> 3 glyph 0.000 25.824  2702        14 #000000    NA     NA    NA     NA NA NA
#>    lwd text font_style path codepoint
#> 1   NA <NA>         NA NULL        NA
#> 2 1.32 <NA>         NA NULL        NA
#> 3   NA <NA>         NA 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
# }