Question

我正在尝试将空间点数据连接到空间多边形数据。

前段时间，这个非常有用的帖子发布了： How to pick up the information for the nearest associated polygon to points using R?

并交叉链接：https://gis.stackexchange.com/questions/18726/spatial-distance-join-between-polygon-and-points-using-r

我正在尝试使用OP发布的代码：

library(rgeos)
library(sp) 
library(maptools)
library(rgdal)
library(sp)

ky.map <- readShapeSpatial("~/KYcounties.shp") 

points.xy <- readShapeSpatial('~/points.shp') # Sample data of the points file 
                                              # is below.

我正在使用的功能是

IntersectPtWithPoly <- function(x, y) { 
# Extracts values from a SpatialPolygonDataFrame with SpatialPointsDataFrame,
# and appends table (similar to ArcGIS intersect)
# Args: 
#   x: SpatialPoints*Frame
#   y: SpatialPolygonsDataFrame
# Returns:
# SpatialPointsDataFrame with appended table of polygon attributes
# Set up overlay with new column of join IDs in x
z <- overlay(y, x)
# Bind captured data to points dataframe
x2 <- cbind(x, z)
# Make it back into a SpatialPointsDataFrame 
# Account for different coordinate variable names 
if(("coords.x1" %in% colnames(x2)) & ("coords.x2" %in% colnames(x2))) {
  coordinates(x2) <- ~coords.x1 + coords.x2
} else if(("x" %in% colnames(x2)) & ("x" %in% colnames(x2))) {
  coordinates(x2) <- ~x + y
}

# Reassign its projection if it has one
if(is.na(CRSargs(x@proj4string)) == "FALSE") {
  x2@proj4string <- x@proj4string
}
return(x2)
}

并被称为

test <- IntersectPtWithPoly(points.xy, ky.map)

除非得到：

，哪个效果很好

Warning message: 'overlay' is deprecated. Use 'over' instead.

以及连接多边形字段的一堆NA。

足够公平：

z <- over(y, x)

但这让我：

Error in data.frame(..., check.names = FALSE) : arguments imply differing
number of rows: 96, 121

以下是我正在使用的点数据示例（放入QGIS并导出为shapefile）：

structure(list(ID = c(5L, 11L, 33L, 41L, 73L, 119L, 175L, 206L, 
216L, 229L), Latitude = c(38.239829, 38.9231075, 38.04169866, 
38.13953849, 38.14800534, 37.85059283, 38.17820492, 38.00833019, 
38.22189947, 36.87255699), Longitude = c(-85.746211, -84.4108925, 
-84.49738797, -85.6776972, -85.02502406, -84.57452618, -85.56667237, 
-84.42084641, -85.48653626, -84.22021486)), .Names = c("ID", 
"Latitude", "Longitude"), row.names = c(NA, 10L), class = "data.frame")

我在Google云端硬盘上分享了shapefile：https://docs.google.com/file/d/0B1bNxpx4XS8dSFJlOTlQSUw0LTg/edit?usp=sharing

思想？

Answer 1

使用spatialEco库有一个简单的解决方案。

library(spatialEco)

# intersect points in polygon
  pts <- point.in.poly(pts, ply)

# check plot
  plot(ply)
  plot(a, add=T)

# convert to data frame, keeping your data
  pts <- as.data.frame(pts)

将点连接到多边形

1 个答案: