R OSRM calculate travel distance within data.frame

Question

Using the osrm package, I want to calculate the distance between two points stored in two different columns of a data frame and put it into a new column.

Doing the following, however, does not work and throws the error: object 'lon' not found. What did go wrong here?

pacman::p_load(
  tidyverse,
  sf,
  osrm
)


test_1 <- data.frame(name_1 = c("a", "b"), long = c(13.371871012201932, 13.445856720780322), lat = c(52.5212875734526, 52.503693991115206)) %>%
    st_as_sf(coords = c("long", "lat"), crs = 4326) %>%
    rename(geom_1 = "geometry")

test_2 <- data.frame(name_2 = c("c", "d"), long = c(13.401224766110927, 13.349212418670756), lat = c(52.51946945798967, 52.5149481833963)) %>%
    st_as_sf(coords = c("long", "lat"), crs = 4326) %>%
    rename(geom_2 = "geometry")

comb <- expand_grid(test_1, test_2)


routes <- comb %>%
    mutate(distances = osrmRoute(
        src = geom_1,
        dst = geom_2,
        returnclass = "sf"
    )$distance)

user_13661061 · Answer

The problem is that an sf object can only have one geom column active at a time. To get around this, just call the sf objects test1 and test2 and it should work.

Please find below the modified code and the corresponding output.

Code

routes <- comb %>%
  mutate(distances = osrmRoute(
    src = test_1,
    dst = test_2,
    returnclass = "sf"
  )$distance)

Output:

routes
# A tibble: 4 x 5
  name_1              geom_1 name_2              geom_2 distances
                            
1 a      (13.37187 52.52129) c      (13.40122 52.51947)      4.35
2 a      (13.37187 52.52129) d      (13.34921 52.51495)      4.35
3 b      (13.44586 52.50369) c      (13.40122 52.51947)      4.35
4 b      (13.44586 52.50369) d      (13.34921 52.51495)      4.35

Alternatively, you can specify which geom column is active in your sf object comb and you will get the same result as above.

Alternative code

routes <- comb %>% mutate(distances = osrmRoute(
  src = st_sf(.,sf_column_name = "geom_1"),
  dst = st_sf(.,sf_column_name = "geom_2"),
  returnclass = "sf"
)$distance)

EDIT

As a follow-up to the exchanges I had with @Jindra Lacko (cf. comments below), I propose a computeDistances() function which can help you to get what you wish. Please find below the code of the function along with its output using your object comb

Code of the function computeDistances

computeDistances <- function(x){  
  
  distances <- data.frame(Distances = numeric())
  
  for (i in seq(x)){
    distances[i,"Distances"]  <- osrmRoute(
      src = st_sf(x,sf_column_name = "geom_1")[i,],
      dst = st_sf(x,sf_column_name = "geom_2")[i,],
      returnclass = "sf"
    )$distance
  }
  
  results <- st_sf(cbind(x, distances))
  
  return(results)
}

Test of the function using your comb object

computeDistances(comb)

Simple feature collection with 4 features and 3 fields
Active geometry column: geom_1
Geometry type: POINT
Dimension:     XY
Bounding box:  xmin: 13.37187 ymin: 52.50369 xmax: 13.44586 ymax: 52.52129
Geodetic CRS:  WGS 84
  name_1 name_2 Distances                    geom_1                    geom_2
1      a      c    4.3543 POINT (13.37187 52.52129) POINT (13.40122 52.51947)
2      a      d    2.6576 POINT (13.37187 52.52129) POINT (13.34921 52.51495)
3      b      c    4.4650 POINT (13.44586 52.50369) POINT (13.40122 52.51947)
4      b      d    8.1611 POINT (13.44586 52.50369) POINT (13.34921 52.51495)

R OSRM calculate travel distance within data.frame

1 Answers