问题描述
我使用 maptools
包中的 readShapePoly
读取了 shapefile,但无法使用 readOGR
读取该文件.我希望有人能够帮助我使用 readOGR
阅读 shapefile.
I have read a shapefile using readShapePoly
in the maptools
package, but cannot read that same file with readOGR
. I am hoping someone may be able to help me read the shapefile with readOGR
.
我从这里下载了文件 orcounty.shp
:http://geography.uoregon.edu/geogr/topics/maps.htm
I downloaded the file orcounty.shp
from here: http://geography.uoregon.edu/geogr/topics/maps.htm
我还下载了相关文件:orcounty.shx
、orcounty.sbx
、orcounty.sbn
和 orcounty.dbf
并将所有五个文件放在文件夹中:c:/users/mark w miller/gis_in_R/shapefile_example/
I also downloaded the associated files: orcounty.shx
, orcounty.sbx
, orcounty.sbn
, and orcounty.dbf
and put all five files in the folder: c:/users/mark w miller/gis_in_R/shapefile_example/
以下代码读取 shapefile 并显示一些属性:
The following code reads the shapefile and displays some attributes:
library(maptools)
setwd('c:/users/mark w miller/gis_in_R/shapefile_example/')
# Oregon county census data (polygons)
orcounty.poly <- readShapePoly('orcounty.shp', proj4string=CRS("+proj=longlat"))
orcounty.line <- readShapeLines('orcounty.shp', proj4string=CRS("+proj=longlat"))
# see projection
summary(orcounty.poly)
Object of class SpatialPolygonsDataFrame
Coordinates:
min max
x -124.55840 -116.46944
y 41.98779 46.23626
Is projected: FALSE
proj4string : [+proj=longlat]
Data attributes:
但是,当我尝试使用以下代码读取同一个 shapefile 时,我收到一个错误:
However, when I try to read that same shapefile using the following code I receive an error:
library(rgdal)
# read shapefile
oregon.map <- readOGR(dsn="c:/users/mark w miller/gis_in_R/shapefile_example/", layer="orcounty")
# convert to dataframe
oregon.map_df <- fortify(oregon.map)
错误信息说:
Error in ogrInfo(dsn = dsn, layer = layer, encoding = encoding, use_iconv = use_iconv) :
Cannot open file
我可以使用以下方法读取 Natural Earth http://www.naturalearthdata.com/ 形状文件:
I can read Natural Earth http://www.naturalearthdata.com/ shapefiles using:
library(rgdal)
setwd("c:/users/mark w miller/gis_in_R/")
# read shapefile
wmap <- readOGR(dsn="ne_110m_physical", layer="ne_110m_land")
因此,自然地球形状文件和俄勒冈形状文件orcounty.shp
之间显然存在差异.
So, apparently there is a difference between the Natural Earth shapefiles and the Oregon shapefile orcounty.shp
.
感谢您提供有关如何使用 readOGR
阅读 orcounty.shp
的任何建议.我的问题类似于这里的问题:rgdal/readOGR - 无法阅读来自 .zip 的 shapefile
Thank you for any advice on how to read orcounty.shp
with readOGR
. My question is similar to the question here: rgdal / readOGR - unable to read shapefile from .zip
推荐答案
尝试从文件路径中删除最后一个/".
Try to remove your last '/' from file path.
readOGR(dsn = 'c:/users/mark w miller/gis_in_R/shapefile_example',
layer = 'orcounty')
这篇关于使用 readOGR 与 readShapePoly 读取形状文件的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!