flightpathr

commit da7705cec5650b6a09891608121f9fb8f9c2ce01
parent c4dc250d8eeb3bac3a8af8d4a2ad3492f0a803dc
Author: eamoncaddigan <eamon.caddigan@gmail.com>
Date:   Wed, 27 Apr 2016 12:02:11 -0400

Input checking.

Diffstat:
M
R/coordsToBearing.R
 | 
10
+++++++---
M
tests/testthat/test_coordsToBearing.R
 | 
4
++++

2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/R/coordsToBearing.R b/R/coordsToBearing.R
@@ -9,8 +9,12 @@
 #' @export
 coordsToBearing <- function(trajectory) {
   trajectoryCoords <- get3dCoords(trajectory)
-  numCoords <- nrow(trajectoryCoords)
-  bearings <- geosphere::bearing(trajectoryCoords[1:(numCoords-1), 1:2],
-                                 trajectoryCoords[2:numCoords, 1:2])
+  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])
   return(c(bearings, NA))
 }
diff --git a/tests/testthat/test_coordsToBearing.R b/tests/testthat/test_coordsToBearing.R
@@ -1,6 +1,10 @@
 library(flightpathr)
 context("coordsToBearing")
 
+test_that("Input checking works", {
+  expect_error(coordsToBearing(matrix(c(-74.577166, 39.457583), nrow = 1)))
+})
+
 test_that("Equatorial routes have constant bearing", {
   trajectory1 <- cbind(longitude = seq(-180, 180, length.out = 100),
                        latitude = 0)