在R中计算点到最近栅格单元边缘的距离

需要计算点要素与最近30×30米栅格单元边缘之间的米制距离。数据按2016-2020年的季度聚合，需逐年逐季度迭代执行该计算。栅格单元的值无关紧要，仅需获取指定季度和年份下每个点到最近栅格单元的矢量距离。

library(raster)
library(sf) # 补充sf包依赖，用于创建矢量点要素

# 设置研究区范围
ext <- extent(401000, 402000, 4405000, 4406000)

# 创建包含投放点位的点文件
set.seed(123) # 设置随机种子保证结果可复现
years <- c(2016, 2017, 2018, 2019, 2020)
quarters <- c("Q1", "Q2", "Q3", "Q4")
coords <- expand.grid(year = years, quarter = quarters, 
                      x = runif(4, 401000, 402000), 
                      y = runif(4, 4405000, 4406000))
points <- st_as_sf(coords, coords = c("x", "y"), crs = st_crs(3310))
points$year <- as.factor(points$year)
points$quarter <- as.factor(points$quarter)

# 创建包含生物量估算值的栅格文件
raster <- raster(ext, res = 30)
values(raster) <- NA
non_empty_cells <- sum(runif(ncell(raster)) > 0.98)
if (non_empty_cells > 0) {
  values(raster)[sample(which(is.na(values(raster))), non_empty_cells)] <- runif(non_empty_cells, 0, 10)
}

# 绘制数据
plot(raster, col = gray.colors(10, start = 0.8, end = 0))
plot(points, add = TRUE, col="red")

内容的提问来源于stack exchange，提问作者Joshua Smith