qtm: Quick thematic map plot

In r-tmap/tmap: Thematic Maps

Quick thematic map plot

Description

Draw a thematic map quickly. This function is a convenient wrapper of the main plotting method of stacking tmap-elements. Without arguments or with a search term, this functions draws an interactive map.

Usage

qtm(
  shp,
  fill = tm_const(),
  col = tm_const(),
  size = tm_const(),
  shape = tm_const(),
  lwd = tm_const(),
  lty = tm_const(),
  fill_alpha = tm_const(),
  col_alpha = tm_const(),
  text = tm_const(),
  text_col = tm_const(),
  text_size = tm_const(),
  by = NULL,
  scale = NULL,
  title = NULL,
  crs = NULL,
  bbox = NULL,
  basemaps = NULL,
  overlays = NULL,
  zindex = NA,
  group = NA,
  group.control = "check",
  style = NULL,
  format = NULL,
  ...
)

Arguments

shp	One of: shape object, which is an object from a class defined by the sf or stars package. Objects from the packages sp and raster are also supported, but discouraged. Not specified, i.e. qtm() is executed. In this case a plain interactive map is shown. An OpenStreetMap search string, e.g. qtm("Amsterdam"). In this case a plain interactive map is shown positioned according to the results of the search query (from OpenStreetMap nominatim)
fill, col, size, shape, lwd, lty, fill_alpha, col_alpha	Visual variables.
text, text_col, text_size	Visual variables.
by	data variable name by which the data is split, or a vector of two variable names to split the data by two variables (where the first is used for the rows and the second for the columns). See also tm_facets().
scale	numeric value that serves as the global scale parameter. All font sizes, symbol sizes, border widths, and line widths are controlled by this value. The parameters symbols.size, text.size, and lines.lwd can be scaled separately with respectively symbols.scale, text.scale, and lines.scale. See also ....
title	main title. For legend titles, use X.style, where X is the layer name (see ...).
crs	Either a crs object or a character value (PROJ.4 character string). By default, the projection is used that is defined in the shp object itself.
bbox	bounding box. Argument passed on to tm_shape()
basemaps	name(s) of the provider or an URL of a tiled basemap. It is a shortcut to tm_basemap(). Set to NULL to disable basemaps. By default, it is set to the tmap option basemaps.
overlays	name(s) of the provider or an URL of a tiled overlay map. It is a shortcut to tm_tiles().
zindex	zindex
group	group
group.control	group.control
style	Layout options (see tm_layout()) that define the style. See tmap_style() for details.
format	Layout options (see tm_layout()) that define the format. See tmap_format() for details.
...	arguments passed on to the ⁠tm_*⁠ functions. The prefix of these arguments should be with the layer function name without "tm_" and a period. For instance, the palette for polygon fill color is called fill.palette. The following prefixes are supported: shape., fill., borders., polygons., symbols., dots., lines., raster., text., layout., grid., facets., and view.. Arguments that have a unique name, i.e. that does not exist in any other layer function, e.g. convert2density, can also be called without prefix.

Details

The first argument is a shape object (normally specified by tm_shape()). The next arguments, from fill to raster, are the aesthetics from the main layers. The remaining arguments are related to the map layout. Any argument from any main layer function, such as tm_polygons(), can be specified (see ...). It is also possible to stack tmap-elements on a qtm plot. See examples.

By default, a scale bar is shown. This option can be set with tmap_options() (argument qtm.scalebar). A minimap is shown by default when qtm is called without arguments of with a search term. This option can be set with tmap_options() (argument qtm.minimap).

Value

A tmap-element

References

Tennekes, M., 2018, tmap: Thematic Maps in R, Journal of Statistical Software, 84(6), 1-39, \Sexpr[results=rd]{tools:::Rd_expr_doi("10.18637/jss.v084.i06")}

See Also

vignette("tmap_sneak_peek")

Examples

data(World, rivers, metro)

# just the map
qtm(World)

# choropleth
qtm(World, fill = "economy", format = "World", style = "col_blind", projection = "+proj=eck4")

# choropleth with more specifications
qtm(World, fill="HPI", fill.n = 9, fill.palette = "div",
    fill.title = "Happy Planet Index", fill.id = "name", 
    style = "gray", format = "World", projection = "+proj=eck4")
# this map can also be created with the main plotting method,
# which is recommended in this case.
## Not run: 
tm_shape(World, projection = "+proj=eck4") +
    tm_polygons("HPI", n = 9, palette = "div",
        title = "Happy Planet Index", id = "name") +
tm_style("gray") +
tm_format("World")

## End(Not run)

# bubble map
## Not run: 
qtm(World, borders = NULL) + 
qtm(metro, symbols.size = "pop2010", 
    symbols.title.size= "Metropolitan Areas", 
    symbols.id= "name",
    format = "World")

## End(Not run)

# dot map
## Not run: 
current.mode <- tmap_mode("view")
qtm(metro, bbox = "China")
tmap_mode(current.mode) # restore mode

## End(Not run)

## Not run: 
# without arguments, a plain interactive map is shown (the mode is set to view)
qtm()

# search query for OpenStreetMap nominatim
qtm("Amsterdam")

## End(Not run)

r-tmap/tmap documentation built on June 23, 2024, 9:58 a.m.