flightpathr

commit f624ff46dfbe3f66a1d7caedef663f4bf65df726
parent e4df477e28518a1c99f8b8f9b3bc7827c916d384
Author: eamoncaddigan <eamon.caddigan@gmail.com>
Date:   Wed, 21 Sep 2016 13:17:49 -0400

coordsToBearing() takes lon/lat pairs for real.

Diffstat:
M
R/coordsToBearing.R
 | 
13
+++++--------

1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/R/coordsToBearing.R b/R/coordsToBearing.R
@@ -1,18 +1,15 @@
-#' Calculate the bearing between successive points in a trajectory.
+#' Calculate the bearing between successive longitude/latitude points.
 #'
-#' @param trajectory A matrix or SpatialPoints object indicating the trajectory
-#'   of an aircraft.
+#' @param longitude Latitude values.
+#' @param latitude Longitude values.
 #' @return The numeric vecotor giving the instantaneious bearing at each point
 #'   along the trajectory, in degrees. This will have the same length as the
 #'   trajectory, but the last element will be \code{NA}.
 #'
 #' @export
-coordsToBearing <- function(trajectory) {
-  trajectoryCoords <- get3dCoords(trajectory)
+coordsToBearing <- function(longitude, latitude) {
+  trajectoryCoords <- cbind(longitude, latitude)
   numPoints <- nrow(trajectoryCoords)
-  if (numPoints < 2) {
-    stop("At least two time points must be specified")
-  }
 
   bearings <- geosphere::bearing(trajectoryCoords[1:(numPoints-1), 1:2],
                                  trajectoryCoords[2:numPoints, 1:2])