setwd('E:/R_test/corrd/')
getwd()
library(readxl)
library(maptools)
library(rgdal)
library(rgeos)
library(sf)
library(sp)
library(ggplot2)
library(terra)
library(raster)
pointread=read_excel('E:/R_test/corrd/loglat.xlsx',col_names = T)
pointcrs=st_crs(pointread) #读取point坐标下。显示无
pointmatric=as.matrix(unlist(pointread))#dataframe转换为矩阵形式
rowcol=matrix(pointmatric,nrow = 5,ncol = 3)#设置矩阵的行列数,统一形式
createpoint=st_multipoint(rowcol,dim = 'xy')#创建sfg多点几何对象 multipoint
问题1:为createpoint添加crs坐标系无法添加