计算坐标和参考点之间的距离

Question

我想计算 lat1、lon1 和参考点（52.92343、5.04127）之间的距离。我想对我的数据集中的每一行都这样做，所以距离将使用每一行中的参考来计算。这意味着我将创建一个以公里为单位的新列。我可以想象你将不得不使用某种循环函数，但到目前为止我还没有弄清楚如何完成这个。我想我将不得不使用包geodist 或geosphere，但不幸的是没有成功。如何计算这些距离？

structure(list(Day = c("26", "05", "17", "18", "19", "19"), Month = c("07", 
"08", "08", "08", "08", "08"), Year = c("2021", "2021", "2021", 
"2021", "2021", "2021"), Location.Receiver = c("Den Oever Ijsselmeer", 
"Medemblik Ijsselmeer, gemaal", "Den Oever Ijsselmeer", "Den Oever Ijsselmeer", 
"Den Oever Ijsselmeer", "Den Oever Ijsselmeer"), Transmitter = c("A69-1602-59776", 
"A69-1602-59777", "A69-1602-59776", "A69-1602-59776", "A69-1602-59769", 
"A69-1602-59776"), Batch.location = c("Den Oever", "Den Oever", 
"Den Oever", "Den Oever", "Den Oever", "Den Oever"), BatchNr = c(8, 
9, 8, 8, 1, 8), Latitude = c(52.92343, 52.76098, 52.92343, 52.92343, 
52.92343, 52.92343), Longitude = c(5.04127, 5.12172, 5.04127, 
5.04127, 5.04127, 5.04127), Date = structure(c(18834, 18844, 
18856, 18857, 18858, 18858), class = "Date")), row.names = c(1095729L, 
1180267L, 1072657L, 1092667L, 716601L, 1077415L), class = "data.frame")

Answer 1

无需循环，您可以使用geodist 计算x 中的坐标数组中的条目与y 中的单个点之间的距离。只需将坐标作为 lon/lat 显式传递并作为数字向量保存回Distance，而不是作为原始矩阵输出。

library(geodist)

df$Distance <- as.numeric(geodist(df[,9:8], c(5.04127, 52.92343)))
#> object has no named columns; assuming order is lon then lat

df$Distance
#> [1]     0.00 18843.92     0.00     0.00     0.00     0.00

Answer 2

请使用 sf 和 units 库找到替代解决方案（参见下面的代表）

Reprex

• 代码

library(sf)
library(units)

# Convert the df into 'sf' object
df_sf <- df %>% 
  st_as_sf(coords = c("Longitude", "Latitude"), crs = 4326)

# Create the reference 'sf' object
ref_point_sf <- st_point(c(5.04127, 52.92343)) %>% 
  st_coordinates() %>% 
  as.data.frame() %>% 
  st_as_sf(coords = c("X", "Y"), crs = 4326)

# Compute the distance between the reference point and points from 'df_sf'
results <- st_distance(ref_point_sf, df_sf) %>% 
  set_units("km")

• 输出

results
#> Units: [km]
#>      [,1]     [,2] [,3] [,4] [,5] [,6]
#> [1,]    0 18.85446    0    0    0    0

^{由reprex package (v2.0.1) 于 2021-12-01 创建}

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• 代码

library(sf)
library(units)
library(dplyr)


# Convert df into 'sf' object
df_sf <- df %>% 
  st_as_sf(coords = c("Longitude", "Latitude"), crs = 4326)

# Create the reference 'sf' object
ref_point_sf <- st_point(c(5.04127, 52.92343)) %>% 
  st_coordinates() %>% as.data.frame() %>% 
  st_as_sf(coords = c("X", "Y"), crs = 4326)

# Compute the distance between the reference point and points from 'df_sf'
results <- st_distance(df_sf, ref_point_sf) %>% 
  set_units("km") %>% 
  as.data.frame() %>% 
  drop_units() %>% 
  `colnames<-`(., "dist_km")

# Add 'results' in the original dataframe
df <- df %>% 
  mutate(dist_km = results)

• 输出

df
#>         Day Month Year            Location.Receiver    Transmitter
#> 1095729  26    07 2021         Den Oever Ijsselmeer A69-1602-59776
#> 1180267  05    08 2021 Medemblik Ijsselmeer, gemaal A69-1602-59777
#> 1072657  17    08 2021         Den Oever Ijsselmeer A69-1602-59776
#> 1092667  18    08 2021         Den Oever Ijsselmeer A69-1602-59776
#> 716601   19    08 2021         Den Oever Ijsselmeer A69-1602-59769
#> 1077415  19    08 2021         Den Oever Ijsselmeer A69-1602-59776
#>         Batch.location BatchNr Latitude Longitude       Date  dist_km
#> 1095729      Den Oever       8 52.92343   5.04127 2021-07-26  0.00000
#> 1180267      Den Oever       9 52.76098   5.12172 2021-08-05 18.85446
#> 1072657      Den Oever       8 52.92343   5.04127 2021-08-17  0.00000
#> 1092667      Den Oever       8 52.92343   5.04127 2021-08-18  0.00000
#> 716601       Den Oever       1 52.92343   5.04127 2021-08-19  0.00000
#> 1077415      Den Oever       8 52.92343   5.04127 2021-08-19  0.00000

^{由reprex package (v2.0.1) 于 2021-12-02 创建}

Answer 3

points_in_circle() 从参考点返回给定radius 内的点。以下返回参考点1000km内的所有点：

library(spatialrisk)
points_in_circle(df, lat_center = 52.92343, lon_center = 5.04127, 
                 lon = Longitude, lat = Latitude, radius = 1e6)
#>         Day Month Year            Location.Receiver    Transmitter
#> 1095729  26    07 2021         Den Oever Ijsselmeer A69-1602-59776
#> 1072657  17    08 2021         Den Oever Ijsselmeer A69-1602-59776
#> 1092667  18    08 2021         Den Oever Ijsselmeer A69-1602-59776
#> 716601   19    08 2021         Den Oever Ijsselmeer A69-1602-59769
#> 1077415  19    08 2021         Den Oever Ijsselmeer A69-1602-59776
#> 1180267  05    08 2021 Medemblik Ijsselmeer, gemaal A69-1602-59777
#>         Batch.location BatchNr Latitude Longitude       Date distance_m
#> 1095729      Den Oever       8 52.92343   5.04127 2021-07-26       0.00
#> 1072657      Den Oever       8 52.92343   5.04127 2021-08-17       0.00
#> 1092667      Den Oever       8 52.92343   5.04127 2021-08-18       0.00
#> 716601       Den Oever       1 52.92343   5.04127 2021-08-19       0.00
#> 1077415      Den Oever       8 52.92343   5.04127 2021-08-19       0.00
#> 1180267      Den Oever       9 52.76098   5.12172 2021-08-05   18875.55

^{由reprex package (v2.0.1) 于 2021-12-02 创建}