Goofy plotting of EXIF data

exif_plot.R

# get EXIF and make a map

library(leaflet)
library(lubridate)
library(plyr)

# all my photos are in a directory pre with subdirectories
pre <- "~/Dropbox/Photos/"
paths_to_photos <- c("some_sub_directory"
                    )

# iterate over the directories and get the data
exif_data <- lapply(paths_to_photos, function(x){
  
  # call to exiftool to extract lat, long, altitude and date to tsv
  cmd <- paste0("exiftool -n -gpslatitude -gpslongitude -gpsaltitude -createdate -T ",
                 pre, x, "*.JPG")
  # execute the command on the given directory and read into R
  exif_data <- read.table(pipe(cmd), header=FALSE, sep="\t",
                          stringsAsFactors = FALSE)
  # name the columns
  names(exif_data) <- c( "latitude","longitude", "altitude", "date")
  # get the format of the columns right
  exif_data$longitude <- as.numeric(exif_data$longitude)
  exif_data$latitude <- as.numeric(exif_data$latitude)
  exif_data$altitude <- as.numeric(exif_data$altitude)
  exif_data$date <- ymd_hms(exif_data$date)
  
  return(exif_data)
})

# convert list of data.frames to one big data.frame
exif_data <- ldply(exif_data)

# remove rows with no geodata
exif_data <- exif_data[!is.na(exif_data$latitude),]

# sort by date
exif_data <- exif_data[order(exif_data$date),]

# plot using leaflet
leaflet(exif_data) %>%
  addTiles() %>%
  addPolylines(~longitude, ~latitude, weight=1)

# or do an rgl plot too
library(rgl)
plot3d(x=exif_data$latitude, y=exif_data$long, z=exif_data$altitude)

For sorting, if plyr is loaded, I usually prefer arrange(exif_data, date). Just personal taste ^_^.