缓冲区内湿地类型面积的计算

Question

我对R相当陌生，当我试图计算缓冲区内每种湿地类型的面积时，我都会遇到错误。当我试图按湿地类型对数据进行分组并总结该区域时，我会收到错误的UseMethod () no applicable method for 'group_by' applied to an object of class c(SpatialPolygonsDataFrame).，如何解决这个问题？

library(tidyverse)
library(rgeos)
library(tidyr)
library(sf)

Neosho_wetlands<- readOGR("HU8_11070205_watershed", layer="HU8_11070205_Wetlands")
Spring_wetlands<- readOGR("HU8_11070207_watershed", layer="HU8_11070207_Wetlands")
North_wetlands<- readOGR("HU8_10290104_watershed", layer="HU8_10290104_Wetlands")
South_wetlands<- readOGR("HU8_11070206_watershed", layer="HU8_11070206_Wetlands")

wetlands<-rbind(Neosho_wetlands, Spring_wetlands, North_wetlands, South_wetlands)
rm("Neosho_wetlands", "Spring_wetlands","North_wetlands","South_wetlands")
plot(wetlands)

points<-read.csv("SiteCov.csv")
coordinates(points)<-points[c("long", "lat")]
proj4string(points)<-CRS("+proj=longlat")
points_sp<-spTransform(points, crs(wetlands))

buffer2<-buffer(points_sp[1:32,], 2000)
crop2<-crop(wetlands, buffer2)
plot(crop2)
as.data.frame(crop2)

crop2 %>% group_by(WETLAND_TY) %>%
  summarize(sum("Freshwater Emergent Wetland",
                "Freshwater Forested/Shrub Wetland",
                "Freshwater Pond",
                "Lake",
                "Riverine"))

Answer 1

当前运行as.data.frame(crop2)，但不将其分配给对象。因此，当您将crop2传递给group_by()时，它仍然是一个SpatialPolygonsDataFrame，并且它没有很好地处理它。您应该能够简单地将as.data.frame(crop2)更改为crop2 <- as.data.frame(crop2)并保持良好状态。否则，您可以按照乔纳森在注释中所指出的那样使用st_read()。