Question

我想回答一些问题，偶然发现了这个问题：

Read in all shapefiles in a directory in R

如果措辞更恰当，我发现这个问题会产生更大的影响。

我认为用户打算查询从特定目录批量加载shapefile到R的方法。

我在下面提供我的解决方案。我欢迎任何有关如何通过以下答案加强它的建议。

Answer 1

    #--download shapefiles from here:
    #--https://www.census.gov/geo/maps-data/data/cbf/cbf_cds.html

    wd <- "/My Shapefiles"
    setwd(wd)

    #--store shapefile names as a list
    shp_files <- list.files(wd, pattern = "\\.shp$")

    #--inspect list
    print(shp_files)

    ####################################
    # Batch shapefile loading function #
    ####################################

    rgdal_batch_shp <- function(shp_list) {

      layer_name <- as.character(gsub(".shp","",shp_list))

      shp_spdf <-readOGR(dsn = wd, stringsAsFactors = FALSE, verbose = TRUE, 
                         useC = TRUE, dropNULLGeometries = TRUE, addCommentsToPolygons = TRUE,
                         layer = layer_name, require_geomType = NULL,
                         p4s = NULL, encoding = 'ESRI Shapefile')
    }

    #########################################
    # Pass batch function to shapefile list #
    #########################################

    library(rgdal) #--for readOGR function

    #--Use lapply to pass rgdal_batch_shp function to files list.

    batch_shp_list <- lapply(shp_files, rgdal_batch_shp)

    #--Extract each element in list into its own object

    for (i in seq(batch_shp_list))
      assign(paste("test_shp", i, sep = ""), batch_shp_list[[i]])

从目录批量加载shapefile到R

1 个答案: