pixel_count_ppp {geocausal}

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,
  ...
)

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.

Value

im objects

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)