distance tibble

generates a distance (in meters) output between two set of points within a tibble and flexible with group_by and purrr::pmap

get_distance_m(set1_lat, set1_lon, set2_lat, set2_lon)

Arguments

set1_lat

set1 of latitude coordinates

set1_lon

set1 of longitude coordinates

set2_lat

set2 of latitude coordinates

set2_lon

set2 of longitude coordinates

Value

distance as double vector

Functions

• get_distance_m(): generates a distance (in meters) output between two set of points within a tibble and flexible with group_by and purrr::pmap

References

for more details check geosphere package

Author

Andree Valle-Campos at Emerge, Emergent Diseases and Climate Change Unit - UPCH.

Examples

if (FALSE) {

library(tidyverse)
library(geosphere)
library(purrr)
library(avallecam)

# function alone

get_distance_m(set1_lat = 57.2, set1_lon = -2.08,
               set2_lat = 52.4, set2_lon = -4.08)

# in a tibble this works as a rowwise operation

tibble(
  set1_lat = c(57.2, 47.2), set1_lon = c(-2.08,-12.08),
  set2_lat = c(52.4, 62.4), set2_lon = c(-4.08,-14.08)
) %>%
  mutate(dist_test=pmap_dbl(.l = select(.,set1_lat,set1_lon,set2_lat,set2_lon),
                            .f = get_distance_m))

# with lag or lead rows and group by operations

d <- tibble(run = c(rep(1,6), rep(2,6)),
            grp = c(rep("a",3),rep("b",3),rep("a",3),rep("b",3)),
            lat = rep(c(57.15508, 52.41283, 57.15521,
                        52.41278, 57.14520, 52.41317),2),
            lon = rep(c(-2.07887, -4.07806, -2.07886,
                        -4.07803, -2.07886, -4.07858),2))

d %>%
  group_by(run,grp) %>%
  mutate(dist=pmap_dbl(list(lat,lon,lag(lat),lag(lon)),get_distance_m))

 }