1
我想创建一个空的SpatialLines对象。对于多边形很容易:创建空的空间线对象
SpatialPolygons(list())
对于空间线这不起作用:
SpatialLines(LinesList = list())
Error in bb[1, ] : incorrect number of dimensions
SpatialLines(LinesList = Lines(list(),ID = "a"))
Error in as.list.default(X) :
no method for coercing this S4 class to a vector
SpatialLines(LinesList = Lines(slinelist = Line(coords = cbind(x = c(), y = c())), ID = c()))
Error in (function (classes, fdef, mtable) :
unable to find an inherited method for function ‘coordinates’ for signature ‘"NULL"’
是否有人知道是怎么回事,我可以创建一个空的对象SpatialLines?
解决方法
我找到了一个解决办法,但这可能不是这样做的最佳方式。我生成一个没有长度的空间线:
SpatialLines(list(Lines(Line(coords = cbind(x = c(0,0), y = c(0,0))), ID = "A")))