raster_overlap: Create an overlap raster

In bsmity13/ADePTR: Acoustic Detection Processing and Visualization Tool in R

Description

Takes multiple rasters of presence-only or presence-absence and calculates the overlap.

Usage

raster_overlap(..., background = NA)

Arguments

...	Any number of RasterLayer objects to sum.
background	A value to replace any 0 values with. Either 0 or NA (the default) are the most logical choices.

Details

This function sums the values of all the input rasters and then replaces any 0 values with the background value. Note that this function will accept rasters with values > 1. If that is the case, the user should take caution not to interpret the values as the number of overlapping individuals, but rather, as the sum of all input rasters.

Examples

#Load example data
data(acoustic)

#Process detections
proc.det <- proc_dets(det = acoustic$detections, sta = acoustic$stations)

#Create COAs
coas.60 <- coa_locs(proc.det)

#Initialize a base raster
r.sa <- init_raster(study_area = acoustic$study_area, res = 0.005)

#Use tidy workflow to create presence for multiple individuals

library(dplyr)

#Animal 1
ani1 <- coas.60 %>%
filter(id == unique(id)[1]) %>%
rasterize_dets(r.sa) %>%
raster_pres()

#Animal 2
ani2 <- coas.60 %>%
filter(id == unique(id)[2]) %>%
rasterize_dets(r.sa) %>%
raster_pres()

#Animal 3
ani3 <- coas.60 %>%
filter(id==unique(id)[3]) %>%
rasterize_dets(r.sa) %>%
raster_pres()

#Animal 4
ani4 <- coas.60 %>%
filter(id==unique(id)[4]) %>%
rasterize_dets(r.sa) %>%
raster_pres()

#Calculate overlap
#Presence-only
ani_over <- raster_overlap(ani1, ani2, ani3, ani4)
plot(ani_over)
plot(acoustic$study_area, add=TRUE)
plot(acoustic$land, add=TRUE, col="wheat")

#Presence-abscence
ani_over0 <- raster_overlap(ani1, ani2, ani3, ani4, background = 0)
plot(ani_over0)
plot(acoustic$study_area, add=TRUE)
plot(acoustic$land, add=TRUE, col="wheat")

bsmity13/ADePTR documentation built on Nov. 9, 2019, 12:43 a.m.