R trying to find latitude/longitude data for cities in europe and getting geocode error messege
geocoding, google-maps, r
Solution
You have to geocode just the `cities` column (it's a little confusing that you have a data frame called `cities`, and within it a column called `cities`). When in doubt, try breaking things down into smaller chunks.
For example, try them one at a time ...
cities <- c("ARNHEM","ATHENS","BAAR","CAMBRIDGESHIRE")
library(ggmap)
geocode(cities[1])
## lon lat
## 1 5.89873 51.9851
geocode(cities[2])
## just checking ...
geocode("ATHENS GEORGIA")
## lon lat
## 1 -83.38333 33.95
Now try the vector all at once:
geocode(cities)
## lon lat
## 1 5.8987296 51.98510
## 2 23.7293097 37.98372
## 3 8.5286332 47.19585
## 4 0.0965375 52.27619
Now try with a data frame:
mydat <- read.csv(textConnection("
cities,Freq,lon,lat
ARNHEM,1.00,NA,NA
ATHENS,3.25,NA,NA
BAAR,1.00,NA,NA
BAD VILBEL,1.00,NA,NA
BILTHOVEN,1.00,NA,NA
BOGUS_PLACE,2,NA,NA"))
geocodes <- geocode(as.character(mydat$cities))
mydat <- data.frame(mydat[,1:2],geocodes)
## cities Freq lon lat
## 1 ARNHEM 1.00 5.898730 51.98510
## 2 ATHENS 3.25 23.729310 37.98372
## 3 BAAR 1.00 8.528633 47.19585
## 4 BAD VILBEL 1.00 8.739480 50.18234
## 5 BILTHOVEN 1.00 5.210381 52.13653
## 6 BOGUS_PLACE 2.00 -92.201158 44.49091
I don't know what the result for `BOGUS_PLACE` means ...!!
Problem
I recently posted a question regarding plotting postions on cities in europe as points on a map. See R, get longitude/latitude data for cities and add it to my dataframe cities xlsx file contains about 20000 cities in europe. I got an error message when trying to find the latitude/longitude data using geocode. I have inserted part of the code below: ``` cities <- read.xlsx("EU_city.xlsx",1) # get frequencies freq <- as.data.frame(table(cities)) library(plotrix) freq$Freq <- rescale(freq$Freq, c(1,10)) # c(scale_min, scale_max) # get cities latitude/longitude - kindly provided by google: library(ggmap) lonlat <- geocode(unique(cities)) cities <- cbind(freq, lonlat) error message: Error: is.character(location) is not TRUE ``` I guess the data(cities) in my dataframe is not found in the geocode call. Is there a way to ignore the city in the dtaframe if it is not matched in geocode Update of question after suggestion....... tried geocode(as.character(cities)) Then my frame looks like this: ``` > cities <- cbind(freq, lonlat) > cities cities Freq lon lat 1 ARNHEM 1.00 NA NA 2 ATHENS 3.25 NA NA 3 BAAR 1.00 NA NA 4 BAD VILBEL 1.00 NA NA 5 BILTHOVEN 1.00 NA NA 6 BOCHUM 10.00 NA NA 7 BREDA 3.25 NA NA 8 CAMBRIDGESHIRE 3.25 NA NA 9 DORDRECHT 1.00 NA NA 10 GAOETERSLOH 1.00 NA NA 11 GELSENKIRCHEN 1.00 NA NA 12 GOES 1.00 NA NA 13 GRONINGEN 3.25 NA NA 14 GUMMERSBACH-DIERINGHAUSEN 1.00 NA NA 15 HALSTEREN 1.00 NA NA 16 HANNOVER 1.00 NA NA 17 HARDERWIJK 1.00 NA NA 18 HEERLEN 3.25 NA NA 19 HILVERSUM 1.00 NA NA ``` I got no long/lat data at all, only NA