How can I create a for loop for this code?

The code below accomplishes my goal of calculating the percentage of a home-range overlapping my treatment area. However, I have 190 home-ranges. Any advice on creating a for loop or other methods to automate this process for all home-ranges? Thank you

I do not know how to create a reproducible example in this situation, but I will if anyone can guide me through the process.

library(sf)
library(plyr)
library(amt)
library(raster)
library(mapview)

######################################################
#read in treatment area shapefile
treatment <- st_read('C:\\Users\\kujld016\\Desktop\\All\\Projects\\Brush_Management\\imagery\\Treatment_perimeter.shp')

#check projection
projection(treatment)

#transform treatment shapefile to correct projection
treatment<-st_transform(treatment,'+proj=utm +zone=14 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs')
projection(treatment)

#######################################################
#read in home-range shapefile
home-range <- st_read("C:\\Users\\kujld016\\Desktop\\All\\Projects\\Brush_Management\\KingR_BBM\\contour_95_151_880_25_2 2009-08.shp")

#check projection
projection(home-range)

#transform home-range shapefile projection to match treatment area shapefile
home-range <- st_transform(home-range,'+proj=utm +zone=14 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs')
projection(home-range)

###################################################
#calculate area overlap between home-range shapefile and treatment area shapefile
pi <- st_intersection(treatment,home-range)
st_area(pi)

#calculate percentage of home-range shapefile overlapping treatment area shapefile and add value to new column
home-range$percent_area <- st_area(pi) / st_area(home-range)```

You can modify your script to loop through multiple home ranges like so:

First define your treatment as you have done, assuming that it is the same treatment for each home range:

treatment <- st_read('C:\\Users\\kujld016\\Desktop\\All\\Projects\\Brush_Management\\imagery\\Treatment_perimeter.shp')
treatment <- st_transform(treatment,'+proj=utm +zone=14 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs')

Next, create a list of the 190 shapefile names using list.files(). For this, put all 190 shapefiles into the same folder, ideally somewhere within your parent directory. The path argument in list.files() will point to where. "*.shp" will include any file with the .shp extension.

home.names <- list.files(path = "foldername", pattern = "*.shp")

Now write the loop, which will iterate through each shapefile.

all.home.ranges <- list()

for (shp in 1:length(home.names)) {
    home.range <- st_read(home.names[shp])
    home.range.t <- st_transform(home.range,'+proj=utm +zone=14 +ellps=GRS80 
     +towgs84=0,0,0,0,0,0,0 +units=m +no_defs')
    pi <- st_intersection(treatment, home.range.t)
    home.range.t$percent_area <- st_area(pi) / st_area(home.range.t)
    all.home.ranges[[shp]] <- home.range.t
}

all.home.ranges will be a list with 190 elements, each of which is a different home range.

Note that this loop will likely take awhile to run. I would recommend testing it by changing for (shp in 1:length(home.names)) to for (shp in 1:length(home.names[1:2])), which will only do two iterations.

How can I create a for loop for this code?

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