r - How to handle missing values when using a reverse geocode function? -

i working data (n of 271,848) in r looks follows:

observation   longitude     latitude --------------------------------------       1        116.38800    39.928902       2        53.000000    32.000000       3          na          na       4          na          na 

and using reverse geocode function following post: convert latitude , longitude coordinates country name in r

when run coords2country(points) line, following error:

"error in .checknumericcoerce2double(obj) : non-finite coordinates"

my best guess function not know how treat missing values. when run code on subset of observations (excluding na's/missing values), works.

i attempted modify function (see last line below) fix problem, still produced error referring above.

reproducible example:

data <- data.frame(   observation = 1:5,   longitude = c(116.3880005, 53, -97, na, na),    latitude = c(39.92890167, 32, 32, na, na))  library(sp) library(rworldmap)     coords2country = function(points)        {          countriessp <- getmap(resolution='low')        #countriessp <- getmap(resolution='high') #you use high res map rworldxtra if       concerned detail        # convert our list of points spatialpoints object       #pointssp = spatialpoints(points, proj4string=crs("+proj=longlat +datum=wgs84"))       #! andy modified make crs same rworldmap       #pointssp = spatialpoints(points, proj4string=crs("+proj=longlat +ellps=wgs84 +datum=wgs84 +no_defs"))       # new changes in worldmap means have use new crs (bogdan):       pointssp = spatialpoints(points, proj4string=crs(" +proj=longlat +ellps=wgs84 +datum=wgs84 +no_defs +towgs84=0,0,0"))        # use 'over' indices of polygons object containing each point        indices = over(pointssp, countriessp)        # return admin names of each country       indices$admin         #indices$iso3 # returns iso3 code       #the line below thought resolve problem.       na.action = na.omit         } 

better use instead:

coords2country_nasafe <- function(points) {     bad <- with(points, is.na(lon) | is.na(lat))     result <- character(length(bad))     result[!bad] <- coords2country(points[!bad,])     result }