Error using writeOGR {rgdal} to write gpx file - gpx

Question

I am trying to use writeOGR to create a gpx file of points. writeOGR() will create a shp file with no error, but if I try to write a KML or GPX file I get this error. I'm using R 3.1.1 and rgdal 0.8-16 on Windows (I've tried it on 7 and 8, same issue).
writeOGR(points, driver="KML", layer="random_2014",dsn="C:/Users/amvander/Downloads")
Error in writeOGR(points, driver = "KML", layer = "random_2014", dsn = "C:/Users/amvander/Downloads") :
Creation of output file failed
It is in geographic coordinates, I already figured out that that was important
summary(points)
Object of class SpatialPointsDataFrame
Coordinates:
min max
x -95.05012 -95.04392
y 40.08884 40.09588
Is projected: FALSE
proj4string :
[+proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0]
Number of points: 20
Data attributes:
x y ID
Min. :-95.05 Min. :40.09 Length:20
1st Qu.:-95.05 1st Qu.:40.09 Class :character
Median :-95.05 Median :40.09 Mode :character
Mean :-95.05 Mean :40.09
3rd Qu.:-95.05 3rd Qu.:40.09
Max. :-95.04 Max. :40.10
str(points)
Formal class 'SpatialPointsDataFrame' [package "sp"] with 5 slots
..# data :'data.frame': 20 obs. of 3 variables:
.. ..$ x : num [1:20] -95 -95 -95 -95 -95 ...
.. ..$ y : num [1:20] 40.1 40.1 40.1 40.1 40.1 ...
.. ..$ ID: chr [1:20] "nvsanc_1" "nvsanc_2" "nvsanc_3" "nvsanc_4" ...
..# coords.nrs : num(0)
..# coords : num [1:20, 1:2] -95 -95 -95 -95 -95 ...
.. ..- attr(*, "dimnames")=List of 2
.. .. ..$ : NULL
.. .. ..$ : chr [1:2] "x" "y"
..# bbox : num [1:2, 1:2] -95.1 40.1 -95 40.1
.. ..- attr(*, "dimnames")=List of 2
.. .. ..$ : chr [1:2] "x" "y"
.. .. ..$ : chr [1:2] "min" "max"
..# proj4string:Formal class 'CRS' [package "sp"] with 1 slots
.. .. ..# projargs: chr "+proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0"
can anyone provide any guidance on how to get around this error?
Here are the files I used and the code.
https://www.dropbox.com/sh/r7kz3p68j58c189/AACH0U_PLH7Y6cZW1wdFLQTOa/random_2014

Answer 1

you already figured out these formats will only accept geographic coordinates (lat-long, not projected) and at least for GPX files there are very limited fields allowed, like "name" for the name, "ele" for elevation and "time" for date-time information. The #data fields in your file do not match those and thus cause an error.
It is possible to write those extra fields using
dataset_options="GPX_USE_EXTENSIONS=yes"
in that case they will be added as subclasses in an "extensions" field, but many simple gps receivers will not read or use those fields though. To create a very simple waypoint file with names use the following procedure.
#I will use your dataset points
#if not already re-project your points as lat-long
ll_points <- spTransform(points, CRS("+proj=longlat + ellps=WGS84"))
# use the ID field for the names
ll_points#data$name <- ll_points#data$ID
#Now only write the "name" field to the file
writeOGR(ll_points["name"], driver="GPX", layer="waypoints",
dsn="C:/whateverdir/gpxfile.gpx")
for me this executed and created a working gpx file that my gps accepted with displayed names.

Answer 2

I had some problems implementing the code for input from a simple data.frame and wanted to provide the full code for someone working with that kind of data (instead of from a shapefile). This is simply a very slightly modified answer from #Wiebe's answer, without having to go search out what #Auriel Fournier's original data looked like.Thank you #Wiebe - your answer helped me solve my problem too.
The data look like this:
dat
name Latitude Longitude
1 AP1402_C110617 -78.43262 45.45142
2 AP1402_C111121 -78.42433 45.47371
3 AP1402_C111617 -78.41053 45.45600
4 AP1402_C112200 -78.42115 45.53047
5 AP1402_C112219 -78.41262 45.50071
6 AP1402_C112515 -78.42140 45.43471
Code to get it into GPX for mapsource using writeOGR:
setwd("C:\\Users\\YourfileLocation")
dat <- structure(list(name = c("AP1402_C110617", "AP1402_C111121", "AP1402_C111617",
"AP1402_C112200", "AP1402_C112219", "AP1402_C112515"), Latitude = c(-78.4326169598409,
-78.4243276812641, -78.4105301310195, -78.4211498660601, -78.4126208020092,
-78.4214041610924), Longitude = c(45.4514150332163, 45.4737126348589,
45.4560042609868, 45.5304703938887, 45.5007103937952, 45.4347135938299
)), .Names = c("name", "Latitude", "Longitude"), row.names = c(NA,
6L), class = "data.frame")
library(rgdal)
library(sp)
dat <- SpatialPointsDataFrame(data=dat, coords=dat[,2:3], proj4string=CRS("+proj=longlat +datum=WGS84"))
writeOGR(dat,
dsn="TEST3234.gpx", layer="waypoints", driver="GPX",
dataset_options="GPX_USE_EXTENSIONS=yes")