flightpathr

commit a82806ce3b9a08a20581f37c5f2c141856522c0b
parent 691dfd75b97e68ec178ef8a9c7d71a2a325f0cd1
Author: eamoncaddigan <eamon.caddigan@gmail.com>
Date:   Wed, 21 Sep 2016 12:50:38 -0400

coordsToBearing() dealing directly with lon/lat.

Diffstat:
M
man/coordsToBearing.Rd
 | 
11
++++++-----
M
tests/testthat/test_coordsToBearing.R
 | 
22
+++++++++++-----------

2 files changed, 17 insertions(+), 16 deletions(-)
diff --git a/man/coordsToBearing.Rd b/man/coordsToBearing.Rd
@@ -2,13 +2,14 @@
 % Please edit documentation in R/coordsToBearing.R
 \name{coordsToBearing}
 \alias{coordsToBearing}
-\title{Calculate the bearing between successive points in a trajectory.}
+\title{Calculate the bearing between successive longitude/latitude points.}
 \usage{
-coordsToBearing(trajectory)
+coordsToBearing(longitude, latitude)
 }
 \arguments{
-\item{trajectory}{A matrix or SpatialPoints object indicating the trajectory
-of an aircraft.}
+\item{longitude}{Latitude values.}
+
+\item{latitude}{Longitude values.}
 }
 \value{
 The numeric vecotor giving the instantaneious bearing at each point
@@ -16,6 +17,6 @@ The numeric vecotor giving the instantaneious bearing at each point
   trajectory, but the last element will be \code{NA}.
 }
 \description{
-Calculate the bearing between successive points in a trajectory.
+Calculate the bearing between successive longitude/latitude points.
 }
 
diff --git a/tests/testthat/test_coordsToBearing.R b/tests/testthat/test_coordsToBearing.R
@@ -1,19 +1,19 @@
 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)
   trajectory2 <- cbind(longitude = -74.6,
                        latitude = seq(89, -89, length.out = 100))
 
-  expect_equal(angleDiff(coordsToBearing(trajectory1), rep(90, 100)),
+  expect_equal(angleDiff(coordsToBearing(trajectory1[, "longitude"],
+                                         trajectory1[, "latitude"]),
+                         rep(90, 100)),
                c(rep(0, 99), NA))
-  expect_equal(angleDiff(coordsToBearing(trajectory2), rep(180, 100)),
+  expect_equal(angleDiff(coordsToBearing(trajectory2[, "longitude"],
+                                         trajectory2[, "latitude"]),
+                         rep(180, 100)),
                c(rep(0, 99), NA))
 })
 
@@ -22,17 +22,17 @@ test_that("Non-equatorial routes look OK", {
                                           c(-74.577166, 39.457583),
                                           100)
 
-  expect_equal(coordsToBearing(trajectory)[1],
+  expect_equal(coordsToBearing(trajectory[, "lon"], trajectory[, "lat"])[1],
                geosphere::bearing(trajectory[1, ], trajectory[2, ]))
-  expect_equal(coordsToBearing(trajectory)[99],
+  expect_equal(coordsToBearing(trajectory[, "lon"], trajectory[, "lat"])[99],
                geosphere::bearing(trajectory[99, ], trajectory[100, ]))
-  expect_true(is.na(coordsToBearing(trajectory)[100]))
+  expect_true(is.na(coordsToBearing(trajectory[, "lon"], trajectory[, "lat"])[100]))
 })
 
 test_that("Trajectories are somewhat reversable", {
   trajectory <- geosphere::destPoint(c(-119.841499, 34.426194), b = 68.4,
                                      d = seq(0, by = 40281.88, length.out = 100))
-  bearings <- coordsToBearing(trajectory)
+  bearings <- coordsToBearing(trajectory[, "lon"], trajectory[, "lat"])
   destPoints <- matrix(NA, nrow = 100, ncol = 2)
   destPoints[1, ] <- trajectory[1, ]
   for (r in seq(2,100)) {
@@ -48,5 +48,5 @@ test_that("Repeated long/lats are handled correctly", {
                                           c(-74.577166, 39.457583),
                                           100)
   trajectory <- rbind(trajectory, trajectory[100, ], trajectory[100, ])
-  expect_true(all(is.na(coordsToBearing(trajectory)[c(100, 101)])))
+  expect_true(all(is.na(coordsToBearing(trajectory[, "lon"], trajectory[, "lat"])[c(100, 101)])))
 })