Map layer: text

Map layer that draws symbols Supported visual variables are: text (the text itself) col (color), size (font size), and fontface (font face).

Usage

tm_text(
  text = tm_const(),
  text.scale = tm_scale(),
  text.legend = tm_legend(),
  text.chart = tm_chart_none(),
  text.free = NA,
  size = tm_const(),
  size.scale = tm_scale(),
  size.legend = tm_legend(),
  size.chart = tm_chart_none(),
  size.free = NA,
  col = tm_const(),
  col.scale = tm_scale(),
  col.legend = tm_legend(),
  col.chart = tm_chart_none(),
  col.free = NA,
  col_alpha = tm_const(),
  col_alpha.scale = tm_scale(),
  col_alpha.legend = tm_legend(),
  col_alpha.chart = tm_chart_none(),
  col_alpha.free = NA,
  fontface = tm_const(),
  fontface.scale = tm_scale(),
  fontface.legend = tm_legend(),
  fontface.chart = tm_chart_none(),
  fontface.free = NA,
  fontfamily = NA,
  bgcol = tm_const(),
  bgcol.scale = tm_scale(),
  bgcol.legend = tm_legend(),
  bgcol.chart = tm_chart_none(),
  bgcol.free = NA,
  bgcol_alpha = tm_const(),
  bgcol_alpha.scale = tm_scale(),
  bgcol_alpha.legend = tm_legend(),
  bgcol_alpha.chart = tm_chart_none(),
  bgcol_alpha.free = NA,
  xmod = 0,
  xmod.scale = tm_scale(),
  xmod.legend = tm_legend_hide(),
  xmod.chart = tm_chart_none(),
  xmod.free = NA,
  ymod = 0,
  ymod.scale = tm_scale(),
  ymod.legend = tm_legend_hide(),
  ymod.chart = tm_chart_none(),
  ymod.free = NA,
  angle = 0,
  angle.scale = tm_scale(),
  angle.legend = tm_legend_hide(),
  angle.chart = tm_chart_none(),
  angle.free = NA,
  plot.order = tm_plot_order("size", reverse = FALSE),
  zindex = NA,
  group = NA,
  group.control = "check",
  blend = "over",
  options = opt_tm_text(),
  ...
)

tm_labels(
  text = tm_const(),
  text.scale = tm_scale(),
  text.legend = tm_legend(),
  text.chart = tm_chart_none(),
  text.free = NA,
  size = tm_const(),
  size.scale = tm_scale(),
  size.legend = tm_legend(),
  size.chart = tm_chart_none(),
  size.free = NA,
  col = tm_const(),
  col.scale = tm_scale(),
  col.legend = tm_legend(),
  col.chart = tm_chart_none(),
  col.free = NA,
  col_alpha = tm_const(),
  col_alpha.scale = tm_scale(),
  col_alpha.legend = tm_legend(),
  col_alpha.chart = tm_chart_none(),
  col_alpha.free = NA,
  fontface = tm_const(),
  fontface.scale = tm_scale(),
  fontface.legend = tm_legend(),
  fontface.chart = tm_chart_none(),
  fontface.free = NA,
  fontfamily = "",
  bgcol = tm_const(),
  bgcol.scale = tm_scale(),
  bgcol.legend = tm_legend(),
  bgcol.chart = tm_chart_none(),
  bgcol.free = NA,
  bgcol_alpha = tm_const(),
  bgcol_alpha.scale = tm_scale(),
  bgcol_alpha.legend = tm_legend(),
  bgcol_alpha.chart = tm_chart_none(),
  bgcol_alpha.free = NA,
  xmod = 0,
  xmod.scale = tm_scale(),
  xmod.legend = tm_legend_hide(),
  xmod.chart = tm_chart_none(),
  xmod.free = NA,
  ymod = 0,
  ymod.scale = tm_scale(),
  ymod.legend = tm_legend_hide(),
  ymod.chart = tm_chart_none(),
  ymod.free = NA,
  angle = 0,
  angle.scale = tm_scale(),
  angle.legend = tm_legend_hide(),
  angle.chart = tm_chart_none(),
  angle.free = NA,
  plot.order = tm_plot_order("AREA", reverse = FALSE, na.order = "bottom"),
  zindex = NA,
  group = NA,
  group.control = "check",
  options = opt_tm_labels(),
  ...
)

tm_labels_highlighted(
  text = tm_const(),
  text.scale = tm_scale(),
  text.legend = tm_legend(),
  text.chart = tm_chart_none(),
  text.free = NA,
  size = tm_const(),
  size.scale = tm_scale(),
  size.legend = tm_legend(),
  size.chart = tm_chart_none(),
  size.free = NA,
  col = tm_const(),
  col.scale = tm_scale(),
  col.legend = tm_legend(),
  col.chart = tm_chart_none(),
  col.free = NA,
  col_alpha = tm_const(),
  col_alpha.scale = tm_scale(),
  col_alpha.legend = tm_legend(),
  col_alpha.chart = tm_chart_none(),
  col_alpha.free = NA,
  fontface = tm_const(),
  fontface.scale = tm_scale(),
  fontface.legend = tm_legend(),
  fontface.chart = tm_chart_none(),
  fontface.free = NA,
  fontfamily = "",
  bgcol = tm_const(),
  bgcol.scale = tm_scale(),
  bgcol.legend = tm_legend(),
  bgcol.chart = tm_chart_none(),
  bgcol.free = NA,
  bgcol_alpha = tm_const(),
  bgcol_alpha.scale = tm_scale(),
  bgcol_alpha.legend = tm_legend(),
  bgcol_alpha.chart = tm_chart_none(),
  bgcol_alpha.free = NA,
  xmod = 0,
  xmod.scale = tm_scale(),
  xmod.legend = tm_legend_hide(),
  xmod.chart = tm_chart_none(),
  xmod.free = NA,
  ymod = 0,
  ymod.scale = tm_scale(),
  ymod.legend = tm_legend_hide(),
  ymod.chart = tm_chart_none(),
  ymod.free = NA,
  angle = 0,
  angle.scale = tm_scale(),
  angle.legend = tm_legend_hide(),
  angle.chart = tm_chart_none(),
  angle.free = NA,
  plot.order = tm_plot_order("AREA", reverse = FALSE, na.order = "bottom"),
  zindex = NA,
  group = NA,
  group.control = "check",
  options = opt_tm_labels(),
  ...
)

opt_tm_text(
  points_only = "ifany",
  point_per = "feature",
  on_surface = FALSE,
  shadow = FALSE,
  shadow.col = NA,
  shadow.offset.x = 0.05,
  shadow.offset.y = 0.05,
  halo = FALSE,
  halo.col = NA,
  halo.width = 0.05,
  halo.blur = 0,
  halo.alpha = 0.8,
  just = "center",
  along_lines = FALSE,
  bg.padding = 0.4,
  bg.border = FALSE,
  bg.border.col = "black",
  bg.border.lwd = 1,
  clustering = FALSE,
  point.label = FALSE,
  point.label.gap = 0,
  point.label.method = "SANN",
  remove_overlap = FALSE
)

opt_tm_labels(
  points_only = "ifany",
  point_per = "feature",
  on_surface = FALSE,
  shadow = FALSE,
  shadow.col = NA,
  shadow.offset.x = 0.05,
  shadow.offset.y = 0.05,
  halo = FALSE,
  halo.col = NA,
  halo.width = 0.05,
  halo.blur = 0,
  halo.alpha = 0.8,
  just = "center",
  along_lines = TRUE,
  bg.padding = 0.4,
  bg.border = FALSE,
  bg.border.col = "black",
  bg.border.lwd = 1,
  clustering = FALSE,
  point.label = NA,
  point.label.gap = 0.4,
  point.label.method = "SANN",
  remove_overlap = FALSE
)

Arguments

text, text.scale, text.legend, text.chart, text.free: Visual variable that determines the text. See details. Unit: Character string.
size, size.scale, size.legend, size.chart, size.free: Visual variable that determines the size. See details. Unit: Multiplier of the base font size. size = 1 renders at the default font size, which is 12 pt in plot mode (par("ps")) and 12 px in view mode (consistent by design). size = 1.5 renders at 18 pt / px, etc.
col, col.scale, col.legend, col.chart, col.free: Visual variable that determines the color. See details. Unit: Color – a color name, hex string.
col_alpha, col_alpha.scale, col_alpha.legend, col_alpha.chart, col_alpha.free: Visual variable that determines the color transparency. See details. Unit: Proportion – numeric 0-1 (0 = fully transparent, 1 = fully opaque).
fontface, fontface.scale, fontface.legend, fontface.chart, fontface.free: Visual variable that determines the font face. See details. Unit: "plain", "bold", "italic", or "bold.italic".
fontfamily: The font family. See gpar() for details.
bgcol, bgcol.scale, bgcol.legend, bgcol.chart, bgcol.free: Visual variable that determines the background color. See Details. Unit: Color – a color name, hex string.
bgcol_alpha, bgcol_alpha.scale, bgcol_alpha.legend, bgcol_alpha.chart, bgcol_alpha.free: Visual variable that determines the background color transparency. See Details. Unit: Proportion – numeric 0-1 (0 = fully transparent, 1 = fully opaque).
xmod, xmod.scale, xmod.legend, xmod.chart, xmod.free: Transformation variable that determines the x offset. See details. Unit: Line heights, relative to the label anchor. Positive = right.
ymod, ymod.scale, ymod.legend, ymod.chart, ymod.free: Transformation variable that determines the y offset. See details. Unit: Line heights, relative to the label anchor. Positive = up. the text. See details.
angle, angle.scale, angle.legend, angle.chart, angle.free: Rotation angle Unit: Degrees, clockwise from north (0-360).
plot.order: Specification in which order the spatial features are drawn. See tm_plot_order() for details.
zindex: Controls the stacking order of map layers. Should be set to a value above 400. By default, layers are stacked in call order, starting at 401. See details.
group: Name of the group to which this layer belongs. This is only relevant in view mode, where layer groups can be switched (see group.control)
group.control: In view mode, the group control determines how layer groups can be switched on and off. Options: "radio" for radio buttons (meaning only one group can be shown), "check" for check boxes (so multiple groups can be shown), and "none" for no control (the group cannot be (de)selected).
blend: Compositing operator for layer blending. Default "over" applies no blending. See the "Layer blending" section for the supported values.
options: options passed on to the corresponding opt_<layer_function> function
...: to catch deprecated arguments from version < 4.0
points_only: should only point geometries of the shape object (defined in tm_shape()) be plotted? By default "ifany", which means TRUE in case a geometry collection is specified.
point_per: specification of how spatial points are mapped when the geometry is a multi line or a multi polygon. One of "feature", "segment" or "largest". The first generates a spatial point for every feature, the second for every segment (i.e. subfeature), the third only for the largest segment (subfeature). Note that the last two options can be significant slower.
on_surface: In case of polygons, centroids are computed. Should the points be on the surface? If TRUE, which is slower than the default FALSE, centroids outside the surface are replaced with points computed with sf::st_point_on_surface().
shadow: Shadow behind the text. Logical.
shadow.col: Color of the shadow.
shadow.offset.x, shadow.offset.y: Shadow offset in line heights
halo: Halo behind the text. In plot mode, it is just an outline, in view mode also a subtle glow.
halo.col: Color of the halo.
halo.width: Width (thickness) of the halo outline. In line heights
halo.blur: Blur radius of the halo glow (view mode only). In line heights. Should be sufficiently larger than halo.width in order to see the effect.
halo.alpha: Alpha transparency of the halo
just: justification of the text relative to the point coordinates. Either one of the following values: "left" , "right", "center", "bottom", and "top", or a vector of two values where first value specifies horizontal and the second value vertical justification. Besides the mentioned values, also numeric values between 0 and 1 can be used. 0 means left justification for the first value and bottom justification for the second value. Note that in view mode, only one value is used.
along_lines: logical that determines whether labels are rotated along the spatial lines. Only applicable if a spatial lines shape is used.
bg.padding: The padding of the background in terms of line heights.
bg.border: Should the background have borders?
bg.border.col: Color of the borders
bg.border.lwd: Line width of the borders
clustering: in interactive modes (e.g. "view" mode), should clustering be applied at lower zoom levels? Either FALSE (default), TRUE, or a mode specific specification, e.g. for "view" mode markerClusterOptions.
point.label: logical that determines whether the labels are placed automatically. By default FALSE for tm_text, and TRUE for tm_labels if the number of labels is less than 500 (otherwise it will be too slow).
point.label.gap: numeric that determines the gap between the point and label
point.label.method: the optimization method, either "SANN" for simulated annealing (the default) or "GA" for a genetic algorithm.
remove_overlap: logical that determines whether the overlapping labels are removed

Details

The visual variable arguments (e.g. col) can be specified with a data variable name (e.g., a spatial vector attribute or a raster layer of the object specified in tm_shape()), with a visual value (for col, a color is expected), or with a geometry-derived variable (see below). See vignette: Visual variables.

Multiple values can be specified: in that case facets are created. These facets can be combined with other faceting data variables, specified with tm_facets(). See vignette: Facets.

The *.scale arguments determine the used scale to map the data values to visual variable values. These can be specified with one of the available tm_scale_*() functions. The default is specified by the tmap option (tm_options()) scales.var. See `rvignette: Scales
The *.legend arguments determine the used legend, specified with tm_legend(). The default legend and its settings are determined by the tmap options (tm_options()) legend. . See `rvignette: Legends
The *.chart arguments specify additional charts, specified with tm_chart_, e.g. tm_chart_histogram(). See `rvignette: Charts
The *.free arguments determine whether scales are applied freely across facets, or shared. A logical value is required. They can also be specified with a vector of three logical values; these determine whether scales are applied freely per facet dimension. This is only useful when facets are applied (see tm_facets()). There are maximally three facet dimensions: rows, columns, and pages. This only applies for a facet grid (tm_facets_grid()). For instance, col.free = c(TRUE, FALSE, FALSE) means that for the visual variable col, each row of facets will have its own scale, and therefore its own legend. For facet wraps and stacks (tm_facets_wrap() and tm_facets_stack()) there is only one facet dimension, so the *.free argument requires only one logical value.

Currently, three geometry-derived variables are implemented:

"AREA" (polygons only), which uses the feature area;
"LENGTH" (lines only), which uses the feature length; and
"MAP_COLORS", which assigns values so that adjacent features receive different values, making it particularly suitable for coloring neighbouring polygons.

Note that geometry-derived variables do not generate a legend automatically. If a legend is required, compute the corresponding variable explicitly, for example with sf::st_area(), sf::st_length(), or tmaptools::map_coloring(), and use the resulting values instead.

Visual variable units

Every visual variable maps data values to a specific output unit. Knowing the unit matters when supplying constant values via tm_const(), or output ranges via values.range / values.scale in the scale functions.

Variable	Output unit	Notes
`fill`, `col`, `bgcol`	color	name, hex, or palette string
`fill_alpha`, `col_alpha`, `bgcol_alpha`	proportion 0-1	0 = transparent, 1 = opaque
`size` (symbols, bubbles, squares, dots)	typographic lines	1 line approx. 1/6 inch; scaled by `values.scale`
`size` (circles)	meters	plain numeric or a `units` object
`size` (text, labels)	multiplier	1 = 12 pt (plot) / 12 px (view)
`lwd`	lwd	base R units; 1 lwd approx. 0.75 pt at 96 dpi
`lty`	–	integer 1-6 or name ("solid", "dashed", ...)
`shape`	–	integer `pch` 1-25 or single character
`angle`	degrees	0-360, clockwise from north
`fontface`	–	"plain", "bold", "italic", "bold.italic"

Symbol size (`size` in `tm_symbols`, `tm_bubbles`, `tm_squares`, `tm_dots`)

"Lines" is a typographic unit: one line is approximately 1/6 inch (the default base line-height in R graphics). The global multiplier tmap_options(values.scale = list(size.bubbles = 1.5)) scales all symbol sizes without changing the data mapping.

Circle size (`size` in `tm_circles`)

The value is a geographic radius in meters. A plain numeric vector is interpreted as meters; a units object (from the units package) is automatically converted, so units::as_units(1, "mi") gives a 1-mile radius. Because the radius is geographic, circles scale with zoom in interactive (view) mode – unlike bubble symbols which keep a fixed screen size.

Text size (`size` in `tm_text`, `tm_labels`)

The value is a multiplier of the base font size. size = 1 renders at 12 pt in plot mode (R's default par("ps")) and at 12 px in view mode (gp$cex * 12 px, see tmapLeafletDataPlot.tm_data_text); the two modes are consistent by design.

Layer blending (`blend`)

Blend modes control how a layer's pixels are combined with the pixels beneath it. For each pixel, let $S$ be the source (top layer) RGB value and $D$ be the destination (bottom layer) RGB value, both normalised to $[0, 1]$.

`blend`	Formula	Use case
`"over"`	$S \cdot \alpha + D \cdot (1 - \alpha)$	Standard alpha compositing (default)
`"multiply"`	$S \times D$	Hillshading over colour raster; both layers darken each other
`"screen"`	$1 - (1 - S)(1 - D)$	Inverse of multiply; brightens
`"overlay"`	multiply if $D < 0.5$, screen if $D \geq 0.5$	Boosts contrast; preserves midtones
`"darken"`	$\min(S, D)$	Keeps the darker of the two layers per channel
`"lighten"`	$\max(S, D)$	Keeps the lighter of the two layers per channel

Requires R >= 4.2 and a compatible graphics device (e.g. png(type = "cairo"), svg()). In view mode, blending is applied via CSS mix-blend-mode. See grid::groupGrob() for the full list of supported operators.

zindex and pane names

In view mode, each layer is rendered in a Leaflet pane named "tmap{zindex}" (e.g., "tmap401", "tmap402"), with base tile layers placed in the standard "tile" pane.

Examples

tm_shape(World, bbox = World) +
  tm_text("name", size="pop_est", col="continent",
      col.scale = tm_scale_categorical(values = "seaborn.dark"),
      col.legend = tm_legend_hide(),
      size.scale = tm_scale_continuous(values.scale = 4),
      size.legend = tm_legend_hide())


metro$upside_down = ifelse(sf::st_coordinates(metro)[,2] < 0, 180, 0)
tm_shape(metro) +
  tm_text(text = "name", size = "pop2020",
      angle = "upside_down", size.legend = tm_legend_hide(),
      col = "upside_down",
      col.scale = tm_scale_categorical(values = c("#9900BB", "#228822")),
      col.legend = tm_legend_hide()) +
  tm_title_out("Which Hemisphere?", position = tm_pos_out("center", "top", pos.v = "bottom"))

Usage

Arguments

Details

Visual variable units

Symbol size (size in tm_symbols, tm_bubbles, tm_squares, tm_dots)

Circle size (size in tm_circles)

Text size (size in tm_text, tm_labels)

Layer blending (blend)