R sp:多边形的面积单位 [英] R sp: unit of area of Polygon

问题描述

我使用R读取形状文件，以使用sp程序包分析油田的多边形(使用WGS84的经度-纬度)及其相应区域.不幸的是，我不知道区域输出的单位.例如.该区域的平均产量为0.85单位(最大4.34)，可能不在平方公里内，因为这对于油田来说太小了.

I use R to read in a shape file to analyse with the sp package polygons of oilfields (longitude-latitude with WGS84) and their respective areas. Unfortunately I do not know the unit of the area output. E.g. the area output is on average 0.85 units (max 4.34) which probably is not in square kilometers since this would be much too small for oilfields.

有人知道sp包中Polygons的面输出单位吗?非常感谢！

Does anyone know the unit of the area output of Polygons in the sp package? Many thanks!

推荐答案

要对经纬度坐标中的多边形进行正确的面积计算，最好使用"spTransform"将其转换为度量相等的面积投影预先.另外，您可以使用包geosphere来做

To get a correct area computation for a polygon in lat-lon coordinates, it would be better to convert them to a metric equal-area projection using "spTransform" beforehand. Alternatively, you could use package geosphere which allows to do

用于地理应用程序的球面三角法.即，计算 距离和角度(经度/纬度)的相关度量 位置"

"Spherical trigonometry for geographic applications. That is, compute distances and re- lated measures for angular (longitude/latitude) locations"

例如，此:

require(geosphere)
areaPolygon(mypoly)

(mypoly是spatialPolygons对象)将为您提供其平方千米的面积.

(with mypoly being a spatialPolygons object) will give you its area in square kilometers.

HTH.

这篇关于R sp:多边形的面积单位的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！