[R] Merge data by coordinates

[David Winsemius]

> On Oct 16, 2016, at 6:32 AM, Miluji Sb <milujisb at gmail.com> wrote:
> 
> Dear all,
> 
> I have two dataframe 1 by latitude and longitude but they always do not
> match. Is it possible to merge them (e.g. nearest distance)?
> 
> # Dataframe 1
> structure(list(lat = c(54L, 55L, 51L, 54L, 53L, 50L, 47L, 51L,
> 49L, 54L), lon = c(14L, 8L, 15L, 7L, 6L, 5L, 13L, 5L, 13L, 11L
> ), PPP2000_40 = c(4606, 6575, 6593, 7431, 9393, 10773, 11716,
> 12226, 13544, 14526)), .Names = c("lat", "lon", "PPP2000_40"), row.names =
> c(6764L,
> 8796L, 8901L, 9611L, 11649L, 12819L, 13763L, 14389L, 15641L,
> 16571L), class = "data.frame")
> 
> # Dataframe 2
> structure(list(lat = c(47, 47, 47, 47, 47, 47, 48, 48, 48, 48
> ), lon = c(7, 8, 9, 10, 11, 12, 7, 8, 9, 10), GDP = c(19.09982,
> 13.31977, 14.95925, 6.8575635, 23.334565, 6.485748, 24.01197,
> 14.30393075, 21.33759675, 9.71803675)), .Names = c("lat", "lon",
> "GDP"), row.names = c(NA, 10L), class = "data.frame")

I think you should first do this:

plot(d1$lat,d1$lon)
points(d2$lat,d2$lon, col="red")

And then respond to my suggestion that this is not a well-posed computing problem. Explain why the red dots should have a 1-1 relationship with the black dots.


-- 
David.

> 
> Thank you so much!
> 
> Sincerely,
> 
> Milu
> 
> 	[[alternative HTML version deleted]]
> 
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David Winsemius
Alameda, CA, USA