Reorganise R files and connect with python test code

test.R

@@ -1,2 +1,34 @@
-args <- commandArgs(trailingOnly = TRUE)
-print(args)
+library(XML)
+
+args = commandArgs(trailingOnly = TRUE)
+datadir = 'data'
+session = args[1]
+filename = paste(datadir, '/', session, '.gpx', sep = '')
+print(filename)
+
+shift.vec <- function (vec, shift) {
+  if(length(vec) <= abs(shift)) {
+    rep(NA ,length(vec))
+  }else{
+    if (shift >= 0) {
+      c(rep(NA, shift), vec[1:(length(vec)-shift)]) }
+    else {
+      c(vec[(abs(shift)+1):length(vec)], rep(NA, abs(shift))) } } }
+
+pfile <- htmlTreeParse("data/Rik_Veenboer_2015-11-10_17-21-59.gpx", useInternalNodes = T)
+
+# Get all elevations, times and coordinates via the respective xpath
+elevations <- as.numeric(xpathSApply(pfile, path = "//trkpt/ele", xmlValue))
+times = xpathSApply(pfile, path = "//trkpt/time", xmlValue)
+coords <- xpathSApply(pfile, path = "//trkpt", xmlAttrs)
+
+# Extract latitude and longitude from the coordinates
+lats <- as.numeric(coords["lat",])
+lons <- as.numeric(coords["lon",])
+
+# Put everything in a dataframe and get rid of old variables
+geodf <- data.frame(lat = lats, lon = lons, ele = elevations, time = times)
+rm(list=c("elevations", "lats", "lons", "pfile", "times", "coords"))
+
+# Output head of frame
+print(head(geodf))