flightconflicts

commit 1b99e7365545c71831f982916a682f4b4a1356c7
parent ba0530a9b30d1bc33485ec69bb2efcfabf8f351a
Author: eamoncaddigan <eamon.caddigan@gmail.com>
Date:   Fri, 20 May 2016 16:39:56 -0400

SLoWC is passing its first tests

Diffstat:
M
R/calculateSLoWC.R
 | 
4
++--
A
tests/testthat/test_calculateSLoWC.R
 | 
31
+++++++++++++++++++++++++++++++

2 files changed, 33 insertions(+), 2 deletions(-)
diff --git a/R/calculateSLoWC.R b/R/calculateSLoWC.R
@@ -35,8 +35,8 @@ calculateSLoWC <- function(trajectory1, trajectory2) {
                              lon0, lat0),
                   trajectory2$altitude)
   
-  ac1Velocity <- bearingToXY(trajectory1$bearing, trajectory1$velocity)
-  ac2Velocity <- bearingToXY(trajectory2$bearing, trajectory2$velocity)
+  ac1Velocity <- bearingToXY(trajectory1$bearing, trajectory1$groundspeed)
+  ac2Velocity <- bearingToXY(trajectory2$bearing, trajectory2$groundspeed)
   
   dXYZ <- ac2XYZ - ac1XYZ
   dXYZ[, 3] <- abs(dXYZ[, 3])
diff --git a/tests/testthat/test_calculateSLoWC.R b/tests/testthat/test_calculateSLoWC.R
@@ -0,0 +1,31 @@
+library(flightconflicts)
+context("calculateSLoWC")
+
+library(geosphere)
+
+# I'll attempt to replicate the values in Appendix A of SC-228.
+
+test_that("co-altitude head-on examples match", {
+  kacy <- c(-74.5771667, 39.4575833)
+  # Traveling at 100 kt for 3 nm.
+  ownshipCoords <-  destPoint(kacy, 90, seq(0, 5556, length.out = 108))
+  intruderCoords <- apply(ownshipCoords, 2, rev)
+  
+  ownshipTrajectory <- createTrajectory(ownshipCoords[, 1], ownshipCoords[, 2])
+  intruderTrajectory <- list()
+  hmd <- c(0, 500, 1000, 2000, 3000, 3999, 5000)
+
+  for (i in seq_along(hmd)) {
+    intruderCoordsHMD <- destPoint(intruderCoords, 0, hmd[i]*0.3048)
+    intruderTrajectory[[i]] <- createTrajectory(intruderCoordsHMD[, 1], intruderCoordsHMD[, 2])
+  }
+  
+  # High tolerances to deal with different sampling rates
+  expect_equal(max(calculateSLoWC(ownshipTrajectory, intruderTrajectory[[1]])), 100.00, tolerance = 5)
+  expect_equal(max(calculateSLoWC(ownshipTrajectory, intruderTrajectory[[2]])), 85.65, tolerance = 5)
+  expect_equal(max(calculateSLoWC(ownshipTrajectory, intruderTrajectory[[3]])), 71.47, tolerance = 5)
+  expect_equal(max(calculateSLoWC(ownshipTrajectory, intruderTrajectory[[4]])), 44.42, tolerance = 5)
+  expect_equal(max(calculateSLoWC(ownshipTrajectory, intruderTrajectory[[5]])), 20.00, tolerance = 5)
+  expect_equal(max(calculateSLoWC(ownshipTrajectory, intruderTrajectory[[6]])), 0.02, tolerance = 5)
+  expect_equal(max(calculateSLoWC(ownshipTrajectory, intruderTrajectory[[7]])), 0)
+})