qtm: Quick thematic map plot

Description

Draw a thematic map quickly.

Usage

qtm(shp, fill = NA, symbols.size = NULL, symbols.col = NULL, symbols.shape = NULL, dots.col = NULL, text = NULL, text.size = 1, text.col = NA, lines.lwd = NULL, lines.col = NULL, raster = NA, borders = NA, by = NULL, scale = NA, title = NA, projection = NULL, format = NULL, style = NULL, basemaps = NA, bubble.size = NULL, bubble.col = NULL, ...)

Arguments

shp

shape object, which is one of

In "view" mode (see tmap_mode) there are two other options. 1) If omitted, an interactive map without thematic layers is opened. 2) In addition, if a character is provided, this character is used as a search query for OpenStreetMap nominatim. This will position the interactive map accordingly. Arguments of tm_view, such as set.view can be passed on directly.

fill

either a color to fill the polygons, or name of the data variable in shp to draw a choropleth. Only applicable when shp is type 1 (see above). Set fill=NULL to draw only polygon borders. See also argument borders.

symbols.size

either the size of the symbols or a name of the data variable in shp that specifies the sizes of the symbols. See also the size arugment of tm_symbols. Only applicable when shp is type 1, 2, or 3 (see above).

symbols.col

either the color of the symbols or a name of the data variable in shp that specifies the colors of the symbols. See also the col arugment of tm_symbols. Only applicable when shp is type 1, 2, or 3 (see above).

symbols.shape

either the shape of the symbols or a name of the data variable in shp that specifies the shapes of the symbols. See also the shape arugment of tm_symbols. Only applicable when shp is type 1, 2, or 3 (see above).

dots.col

name of the data variable in shp for the dot map that specifies the colors of the dots. If dots.col is specified instead symbols.col, dots instead of bubbles are drawn (unless symbols.shape is specified).

text

Name of the data variable that contains the text labels. Only applicable when shp is type 1, 2, or 3 (see above).

text.size

Font size of the text labels. Either a constant value, or the name of a numeric data variable. Only applicable when shp is type 1, 2, or 3 (see above).

text.col

name of the data variable in shp for the that specifies the colors of the text labels. Only applicable when shp is type 1, 2, or 3 (see above).

lines.lwd

either a line width or a name of the data variable that specifies the line width. Only applicable when shp is type 3 (see above).

lines.col

either a line color or a name of the data variable that specifies the line colors. Only applicable when shp is type 3 (see above).

raster

either a color or a name of the data variable that specifices the raster colors. Only applicable when shp is type 4, 5, or 6 (see above).

borders

color of the polygon borders. Use NULL to omit the borders.

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, sy mbol sizes, border widths, and line widths are controled by this value. The parameters symbols.size, text.size, and lines.lwd can be scaled seperately 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 ...).

projection

character that determines the projection. Either a PROJ.4 character string or a shortcut. See get_proj4 for a list of shortcut values. By default, the projection is used that is defined in the shp object itself, which can be obtained with get_projection.

format

tm_layout wrapper used for format. Currently available in tmap: "World", "Europe", "NLD", "World_wide", "Europe_wide", "NLD_wide". Own wrappers can be used as well (see details).

style

tm_layout wrapper used for style. Available in tmap: "bw", "classic". Own wrappers can be used as well (see details).

basemaps

basemaps for the view mode. See tm_view

bubble.size

deprecated. Please use symbols.size.

bubble.col

deprecated. Please use symbols.col.

...

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.

Value

tmap-element

Details

This function is a convenient wrapper of the main plotting method of stacking tmap-elements. 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 can be specified (see ...). It is also possible to stack tmap-elements on a qtm plot. See examples.

For format, any character value, say "xxx" can be used if the wrapper function "tm_format_xxx" exists. The same applies for the argument style.

Examples

Run this code

data(World, rivers, metro)

# just the map
qtm(World)

# choropleth
qtm(World, fill = "economy", format="World", style="col_blind")

qtm(World, fill="HPI", fill.n=9, fill.palette="div", fill.auto.palette.mapping=FALSE, 
	fill.title="Happy Planet Index", fill.id="name", format="World", style="gray")

# bubble map
qtm(World, borders = NULL) + 
qtm(metro, symbols.size = "pop2010", 
    symbols.title.size= "Metropolitan Areas", 
    symbols.id= "name",
    format = "World")

# TIP: check out these examples in view mode, enabled with tmap_mode("view")