如何使用distHaversine函数? [英] How to use distHaversine function?

问题描述

我正在尝试在循环中使用R中的distHavrsine函数来计算几百行的某些经纬度坐标之间的距离.在我的循环中，我有以下代码:

I am trying to use the distHavrsine function in R, inside a loop to calculate the distance between some latitude and longitude coordinates for a several hundred rows. In my loop I have this code:

if ((distHaversine(c(file[i,"long"], file[i,"lat"]),
                   c(file[j,"long"], file[j,"lat"]))) < 50 )

在此之后，如果距离小于50米，我希望它记录这些行，并且它所参考的经纬度坐标如下所示:

after which if the distance is less than 50 meters i want it to record those rows, and where the latitude and longitude coordinates it is referencing look like:

0.492399367 30.42530045

和

0.496899361 30.42497045

但是我得到这个错误

.pointsToMatrix(p1)中的错误:纬度> 90

Error in .pointsToMatrix(p1) : latitude > 90

推荐答案

我收到此错误".pointsToMatrix(p1)中的错误:纬度> 90".能有人解释为什么以及如何解决吗?

i get this error "Error in .pointsToMatrix(p1) : latitude > 90". Can anyone explain why and how to solve?

该错误告诉您纬度值大于90，超出范围:

The error tells you that you got latitude values greater than 90, which is out of scope:

library(geosphere)
distHaversine(c(4,52), c(13,52))
# [1] 616422
distHaversine(c(4,52), c(1,91))
# Error in .pointsToMatrix(p2) : latitude > 90

您可以通过仅向 distHaversine 提供坐标在可接受范围内的坐标来解决此问题.

You can solve this issue by only feeding distHaversine with coordinates inside the accepted ranges.

我正在尝试在R中的distHavrsine函数中使用循环计算一些经纬度坐标之间的距离几百行.(...)如果距离小于50米，我要它记录那些行

I am trying to use the distHavrsine function in R, inside a loop to calculate the distance between some latitude and longitude coordinates for a several hundred rows. (...) if the distance is less than 50 meters i want it to record those rows

看看 distm 函数，该函数可以轻松计算出几百行的距离矩阵(即无循环).默认情况下，它使用 distHaversine .例如，要获取比650000米更近的数据帧行:

Have a look at the distm function, which calculates a distance matrix for your few hundred rows easily (i.e. without loops). It uses distHaversine by default. For example, to get the data frame rows that are closer then 650000 meters:

df <- read.table(sep=",", col.names=c("lon", "lat"), text="
4,52
13,52 
116,39")
(d <- distm(df))
#         [,1]    [,2]    [,3]
# [1,]       0  616422 7963562
# [2,]  616422       0 7475370
# [3,] 7963562 7475370       0

d[upper.tri(d, T)] <- NA
( idx <- which(d < 650000, arr.ind = T) )
#      row col
# [1,]   2   1
cbind(df[idx[, 1], ], df[idx[, 2], ])
#   lon lat lon lat
# 2  13  52   4  52

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