Retrieves the precomputed road (driving) distance between Nigerian
state capitals. Both a and b can be vectors of the same
length, in which case distances are computed element-wise.
Usage
ng_distance(a, b, unit = c("km", "miles"))
Arguments
- a, b
Character vector. Name(s) of city/cities (case-insensitive).
Must be the same length; vector recycling is not permitted.
- unit
Character. Unit of distance to return. One of "km" (default) or
"miles".
Value
Numeric vector of road distances in the requested unit (rounded to
1 decimal place), with the same length as a and b.
Details
Distances are approximate driving distances sourced from UNDP.
They represent typical road travel and may vary due to route choice,
road conditions, or detours.
City names are matched case-insensitively.
Examples
ng_distance("Lagos", "Kano")
#> [1] 1139
ng_distance("Abuja", "Port Harcourt", unit = "miles")
#> [1] 382.8
ng_distance("Ibadan", "enugu") # case-insensitive
#> [1] 558
ng_distance(c("Lagos", "Abuja"), c("Kano", "Enugu")) # vectorized
#> [1] 1139 393
