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Layer for counting occurrences of data in spatial relation a location or other sf object

Source: R/layer_count.R
layer_count.Rd

Wraps sfext::count_sf_ext(). Specification of parameters for this function may be too complex and may be changed in the future.

Usage

layer_count(
  data,
  location = NULL,
  y = NULL,
  join = sf::st_intersects,
  largest = TRUE,
  replace_na = FALSE,
  lims = NULL,
  .id = "id",
  grid_params = list(alpha = 1, color = NA),
  show_data = FALSE,
  data_params = list(mapping = aes(), alpha = 0.75, size = 1),
  show_label = FALSE,
  label_params = NULL,
  scale_fn = ggplot2::scale_fill_continuous,
  scale_params = list(type = "viridis", breaks = scales::breaks_pretty(n = 4)),
  ...
)

Arguments

data

Data to count in relationship to y

location

Passed to x parameter of sfext::count_sf_ext().

y

If NULL (default), y defaults to an sf object created by st_make_grid_ext() using x or data (if x is NULL) as the x parameter for st_make_grid_ext(). If not NULL, y must be an sf object that has a column with the same name as .id (defaults to "id").

join

geometry predicate function with the same profile as st_intersects; see details

largest

logical; if TRUE, return x features augmented with the fields of y that have the largest overlap with each of the features of x; see https://github.com/r-spatial/sf/issues/578

replace_na

If TRUE, replace NA values from count with 0.

lims

Optional numeric vector with minimum or both minimum and maximum count values. If provided, any values below the minimum are set to that minimum and any values above the maximum as set to the maximum. If only one value is provided, it is assumed to be a minimum limit.

.id

A name to use for the cell id column. Defaults to "id".

grid_params

Passed to layer_location_data() to style foreground grid with fill based on count.

show_data

If TRUE, add background layer with data to stack returned by function. If TRUE and grid_params includes a fixed aesthetic for alpha, divide alpha in half to ensure background data is visible below the filled grid.

data_params

Passed to layer_location_data() to style background layer based on data.

show_label

If TRUE, add layer with labels to stack returned by function.

label_params

Passed to layer_labelled() for foreground labels with fill based on count.

scale_fn, scale_params

Scale function and parameters. Defaults to ggplot2::scale_fill_continuous().

...

Arguments passed on to sfext::count_sf_ext

wt

<data-masking> Frequency weights. Can be NULL or a variable:

  • If NULL (the default), counts the number of rows in each group.

  • If a variable, computes sum(wt) for each group.

sort

If TRUE, will show the largest groups at the top.

keep_na

If TRUE, filter NA values from count. Ignored if replace_na is TRUE.

geometry

If TRUE (default) return a sf object. If FALSE, return a data frame.

name

The name of the new column in the output.

If omitted, it will default to n. If there's already a column called n, it will use nn. If there's a column called n and nn, it'll use nnn, and so on, adding ns until it gets a new name.

Examples


nc <- sf::read_sf(system.file("shape/nc.shp", package = "sf"))
data <- sf::st_sample(nc, 75)

ggplot() +
  layer_count(data = data, location = nc)


ggplot() +
  layer_count(data = data, y = nc, .id = "FIPS")