ggformula (version 0.9.0)

gf_sf: Mapping with shape files

Description

Mapping with shape files

Usage

gf_sf(object = NULL, gformula = NULL, data = NULL, alpha, color,
  fill, group, linetype, size, geometry, xlab, ylab, title, subtitle,
  caption, stat = "sf", position = "identity", show.legend = NA,
  show.help = NULL, inherit = TRUE, environment = parent.frame(),
  ...)

Arguments

object

When chaining, this holds an object produced in the earlier portions of the chain. Most users can safely ignore this argument. See details and examples.

gformula

A formula with shape y ~ x. Faceting can be achieved by including | in the formula.

data

A data frame with the variables to be plotted.

alpha

Opacity (0 = invisible, 1 = opaque).

color

A color or a formula used for mapping color.

fill

A color for filling, or a formula used for mapping fill.

group

Used for grouping.

linetype

A linetype (numeric or "dashed", "dotted", etc.) or a formula used for mapping linetype.

size

A numeric size or a formula used for mapping size.

geometry

A column of class sfc containing simple features data. (Another option is that data may contain a column named geometry.) geometry is never inherited.

xlab

Label for x-axis. See also gf_labs().

ylab

Label for y-axis. See also gf_labs().

title

Title, sub-title, and caption for the plot. See also gf_labs().

subtitle

Title, sub-title, and caption for the plot. See also gf_labs().

caption

Title, sub-title, and caption for the plot. See also gf_labs().

stat

A character string naming the stat used to make the layer.

position

Either a character string naming the position function used for the layer or a position object returned from a call to a position function.

show.legend

A logical indicating whether this layer should be included in the legends. NA, the default, includes layer in the legends if any of the attributes of the layer are mapped.

show.help

If TRUE, display some minimal help.

inherit

A logical indicating whether default attributes are inherited.

environment

An environment in which to look for variables not found in data.

...

Additional arguments. Typically these are (a) ggplot2 aesthetics to be set with attribute = value, (b) ggplot2 aesthetics to be mapped with attribute = ~ expression, or (c) attributes of the layer as a whole, which are set with attribute = value.

Value

a gg object

Specifying plot attributes

Positional attributes (a.k.a, aesthetics) are specified using the formula in gformula. Setting and mapping of additional attributes can be done through the use of additional arguments. Attributes can be set can be set using arguments of the form attribute = value or mapped using arguments of the form attribute = ~ expression.

In formulas of the form A | B, B will be used to form facets using facet_wrap() or facet_grid(). This provides an alternative to gf_facet_wrap() and gf_facet_grid() that is terser and may feel more familiar to users of lattice.

Evaluation

Evaluation of the ggplot2 code occurs in the environment of gformula. This will typically do the right thing when formulas are created on the fly, but might not be the right thing if formulas created in one environment are used to create plots in another.

See Also

ggplot2::geom_line(), gf_point()

Examples

# NOT RUN {
if (require(maps) && require(maptools) &&
  require(sf) && require(rgeos) &&
  utils::packageVersion("ggplot2") > "2.2.1") {
  US <- sf::st_as_sf(map('state', plot = FALSE, fill = TRUE))
  gf_sf( fill = ~ factor(nchar(ID)), data = US) %>%
  gf_refine(coord_sf())

  # We can specify shape data and external data separately using geometry
  MI <- sf::st_as_sf(map('county', 'michigan', plot = FALSE, fill = TRUE))
  gf_sf(fill = ~ log10(population), data = MIpop %>% dplyr::arrange(county),
        geometry = ~ MI$geometry, color = "white") %>%
  gf_refine(coord_sf(), theme_bw())

  # alternatively we can merge external data and shape data into one data frame.
  MI %>%
    dplyr::mutate(county = gsub("michigan,", "", ID)) %>%
    dplyr::left_join(MIpop %>% dplyr::mutate(county = tolower(county))) %>%
    gf_sf(fill = ~ population/1e3) %>%
  gf_refine(
    coord_sf(), theme_bw(),
    scale_fill_continuous(name = "population (thousands)", trans = "log10"))
}
# }