geocausal (version 0.3.4)

pixel_count_ppp: Get number of events in a pixel

Description

`pixel_count_ppp()` takes a column of hyperframes (ppp objects) and gets the number of events in each pixel.

Usage

pixel_count_ppp(
  data,
  ngrid = c(128, 128),
  W = NULL,
  weights = NULL,
  DivideByPixelArea = FALSE,
  ...
)

Value

im objects

Arguments

data

the name of a hyperframe and column of interest.

ngrid

a number or a vector of two numbers specifying the pixel array dimensions. A single integer, or an integer vector of length 2 giving dimensions in the y and x directions.Default is `c(128,128)`.

W

Optional window mask (object of class `"owin"`) determining the pixel raster. `data` should be in the form of `"hyperframe$column"`.

weights

Optional vector of weights associated with the points.

DivideByPixelArea

Logical value determining whether the resulting pixel values should be devided by the pixel area. Default value is `False`.

...

parameters passed on to the function.

Examples

# Time variable
dat_out <- insurgencies[1:100, ]
dat_out$time <- as.numeric(dat_out$date - min(dat_out$date) + 1)

# Hyperframe
dat_hfr <- get_hfr(data = dat_out,
                   col = "type",
                   window = iraq_window,
                   time_col = "time",
                   time_range = c(1, max(dat_out$time)),
                   coordinates = c("longitude", "latitude"),
                   combine = TRUE)

# Get the number of events for each pixel
pixel_count_ppp(data = dat_hfr$all_combined)