Build facet subplot annotations — build_facet

Creates a list of plotly annotation objects suitable for labelling faceted subplots arranged in a grid of nrows rows. When nrows = 1 (the default) the behaviour matches the previous single-row layout. Optionally appends a shared X-axis title (bottom centre) and a shared, rotated Y-axis title (left centre).

Usage

build_facet_annotations(
  facet_levels,
  x.title = NULL,
  y.title = NULL,
  title.font.size = 14,
  nrows = 1,
  fig = NULL,
  title.offset = 0.02
)

Arguments

facet_levels: Character vector of facet level labels, one per subplot.
x.title: Optional character, shared X-axis title. Default: NULL.
y.title: Optional character, shared Y-axis title. Default: NULL.
title.font.size: Numeric, font size for all annotation text. Default: 14.
nrows: Integer, number of rows the faceted subplots are arranged in. Used to compute per-subplot annotation coordinates for multi-row grids when fig is not supplied. Default: 1.
fig: Optional plotly figure. When supplied, per-panel title coordinates are read directly from the figure's xaxis/yaxis domains so that titles stay aligned with panels after domain-rewriting helpers such as apply_facet_subplot_spacing(). If NULL (the default), coordinates are computed from nrows assuming evenly spaced panels filling the full paper area.
title.offset: Numeric fraction of the figure height to place each subplot title above the top of its panel. Default: 0.02.

Value

A list of annotation lists suitable for plotly::layout(annotations = ...).

Author

Jared Andrews

Examples

build_facet_annotations(c("A", "B", "C"), x.title = "X", y.title = "Y")
#> [[1]]
#> [[1]]$x
#> [1] 0.1666667
#> 
#> [[1]]$y
#> [1] 1.05
#> 
#> [[1]]$xref
#> [1] "paper"
#> 
#> [[1]]$yref
#> [1] "paper"
#> 
#> [[1]]$text
#> [1] "A"
#> 
#> [[1]]$showarrow
#> [1] FALSE
#> 
#> [[1]]$xanchor
#> [1] "center"
#> 
#> [[1]]$yanchor
#> [1] "bottom"
#> 
#> [[1]]$font
#> [[1]]$font$size
#> [1] 14
#> 
#> 
#> 
#> [[2]]
#> [[2]]$x
#> [1] 0.5
#> 
#> [[2]]$y
#> [1] 1.05
#> 
#> [[2]]$xref
#> [1] "paper"
#> 
#> [[2]]$yref
#> [1] "paper"
#> 
#> [[2]]$text
#> [1] "B"
#> 
#> [[2]]$showarrow
#> [1] FALSE
#> 
#> [[2]]$xanchor
#> [1] "center"
#> 
#> [[2]]$yanchor
#> [1] "bottom"
#> 
#> [[2]]$font
#> [[2]]$font$size
#> [1] 14
#> 
#> 
#> 
#> [[3]]
#> [[3]]$x
#> [1] 0.8333333
#> 
#> [[3]]$y
#> [1] 1.05
#> 
#> [[3]]$xref
#> [1] "paper"
#> 
#> [[3]]$yref
#> [1] "paper"
#> 
#> [[3]]$text
#> [1] "C"
#> 
#> [[3]]$showarrow
#> [1] FALSE
#> 
#> [[3]]$xanchor
#> [1] "center"
#> 
#> [[3]]$yanchor
#> [1] "bottom"
#> 
#> [[3]]$font
#> [[3]]$font$size
#> [1] 14
#> 
#> 
#> 
#> [[4]]
#> [[4]]$x
#> [1] 0.5
#> 
#> [[4]]$y
#> [1] -0.1
#> 
#> [[4]]$xref
#> [1] "paper"
#> 
#> [[4]]$yref
#> [1] "paper"
#> 
#> [[4]]$text
#> [1] "X"
#> 
#> [[4]]$showarrow
#> [1] FALSE
#> 
#> [[4]]$xanchor
#> [1] "center"
#> 
#> [[4]]$yanchor
#> [1] "top"
#> 
#> [[4]]$font
#> [[4]]$font$size
#> [1] 14
#> 
#> 
#> 
#> [[5]]
#> [[5]]$x
#> [1] -0.05
#> 
#> [[5]]$y
#> [1] 0.5
#> 
#> [[5]]$xref
#> [1] "paper"
#> 
#> [[5]]$yref
#> [1] "paper"
#> 
#> [[5]]$text
#> [1] "Y"
#> 
#> [[5]]$showarrow
#> [1] FALSE
#> 
#> [[5]]$xanchor
#> [1] "center"
#> 
#> [[5]]$yanchor
#> [1] "middle"
#> 
#> [[5]]$textangle
#> [1] -90
#> 
#> [[5]]$font
#> [[5]]$font$size
#> [1] 14
#> 
#> 
#>