需要帮助重新解决R中的转换问题.
我已经计算了一团云的凸包.我想从构成凸包的点开始构建一个多边形对象,并将其保存为可由GIS软件(ArcMap等)读取的shapefile.
我的代码看起来像这样:
gps <- read.csv(f) ##reads the lat-long coordinates file x <- gps$LONGITUDE ##tells R which columns is which y <- gps$LATITUDE z<-chull(x,y) ##calculates the convex hull --this is just a list of x-y points, N vertex dfHull <-cbind(x[z],y[z]) ##the convex hull expressed as a list of selected x-y points plot(dfHull) ##this plots the vertex of the polygon, just a check lines(dfhull) ##plots the polygon in screen ##generate polygon shapefile, from dfHull, and save it externally as a shapefile ???
源文件仅包含lat-long坐标,例如:
52.73336 N 0.365974 52.7332 N 0.366051 52.73289 N 0.36636 52.73297 N 0.366258 52.73298 N 0.366243 52.733 N 0.366112 52.73308 N 0.365942 52.73317 N 0.365881 52.73321 N 0.36593 52.73328 N 0.365942 52.73352 N 0.36579 52.73362 N 0.365678 52.73391 N 0.365536 52.7373 N 0.36543 52.73289 N 0.36728
我知道有一些软件包(rgdal,maptools,..)来帮助解决这些问题,但我对空间的东西非常不熟悉.我真正需要的是生成多边形对象并将其保存为shapefile.
任何帮助赞赏.在此先感谢,开发.