r - 从 rstudio 中的 shapefile 绘制图层的难度

Question

我正在尝试从一个简单的 shapefile 加载和绘制图层。这是美国的州界。我可以很好地加载它:

> library("sp","rgdal")

> shape = readOGR("/home/username/data/share/mapnik/world_boundaries/states_EPSG4326.shp", layer="states_EPSG4326")

    OGR data source with driver: ESRI Shapefile 
    Source: "/home/username/data/share/mapnik/world_boundaries/states_EPSG4326.shp", layer:       "states_EPSG4326"
    with 2895 features and 9 fields
    Feature type: wkbPolygon with 2 dimensions

但它无法绘制:

> plot(shape)

There were 50 or more warnings (use warnings() to see the first 50)
There were 50 or more warnings (use warnings() to see the first 50)
> warnings()
Warning messages:
1: Path drawing not available for this device
2: Path drawing not available for this device
3: Path drawing not available for this device
...

我错过了什么？绘图窗口中没有显示任何内容。此 shapefile 中只有一个图层。我可以在 qgis 中绘制它，我正在尝试为其寻找替代方案。 R 似乎是一个受欢迎的选择，但到目前为止我运气不佳。我用谷歌搜索了这个警告，但没有发现任何有用的东西。

编辑:
我尝试过的每个形状文件都会收到相同的响应。这是我已验证的 shapefile 以相同的方式响应:

http://dds.cr.usgs.gov/pub/data/nationalatlas/statep010_nt00798.tar.gz

这是 sessionInfo() 的输出:

> sessionInfo()
R version 2.15.2 (2012-10-26)
Platform: x86_64-pc-linux-gnu (64-bit)

locale:
 [1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C         LC_TIME=C           
 [4] LC_COLLATE=C         LC_MONETARY=C        LC_MESSAGES=C       
 [7] LC_PAPER=C           LC_NAME=C            LC_ADDRESS=C        
[10] LC_TELEPHONE=C       LC_MEASUREMENT=C     LC_IDENTIFICATION=C 

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] rgdal_0.7-22 sp_1.0-2    

loaded via a namespace (and not attached):
[1] grid_2.15.2     lattice_0.20-10 tools_2.15.2 

这也是一个 gentoo 系统，在 dev-lang/R 上启用了以下使用标志:

X icu java jpeg nls openmp png readline tiff

未启用以下使用标志(未编译功能):

-bash-completion -cairo -doc -lapack -minimal -perl -profile -static-libs -tk"

对我来说唯一看起来可疑的两个是 cairo 和 tk，它们是否需要用于绘图？

我从终端运行了类似但不完全相同的结果:

> shape = readOGR("/home/username/Downloads/state/statep010.shp", layer="statep010")
OGR data source with driver: ESRI Shapefile 
Source: "/home/username/Downloads/state/statep010.shp", layer: "statep010"
with 62 features and 9 fields
Feature type: wkbPolygon with 2 dimensions
> plot(shape)
There were 50 or more warnings (use warnings() to see the first 50)
> warnings()
Warning messages:
1: In polypath(x = mcrds[, 1], y = mcrds[, 2], border = border,  ... :
  Path drawing not available for this device
2: In polypath(x = mcrds[, 1], y = mcrds[, 2], border = border,  ... :
  Path drawing not available for this device
3: In polypath(x = mcrds[, 1], y = mcrds[, 2], border = border,  ... :
  Path drawing not available for this device
...

Answer 1

使用 plot(shape, usePolypath = FALSE)如 this thread 中所述罗杰·比万德。