tests/testthat/testgeometry.R

In IDInteraction/IDInteractionRpackage: Functions to analyse data from the IDinteraction project

context("Test geometry functions")

test_that("Area calculation works", {
  
  testunitsquare <- data.frame(x=c(0,1,1,0), y=c(0,0,1,1))
  
  expect_equal(calcArea(testunitsquare), 1)
  
  testsquare <- testunitsquare * 2
  
  expect_equal(calcArea(testsquare), 4)
  
  testtriangle <- data.frame(x=c(0,1,1), y=c(0,0,1))
  expect_equal(calcArea(testtriangle), 0.5)
  
  # Hexagon, radius 100.  Nodes calculated from
  testhexagon <- data.frame(x=100*cos( 2*seq(1:6)*pi/6 ), y=100* sin(2*seq(1:6)*pi/6))
  expect_equal(calcArea(testhexagon), 25980.76, tolerance=0.01)
  
  
  # Check invariant to translation
  transhexagon <- testhexagon + 100
  expect_equal(calcArea(transhexagon), calcArea(testhexagon))
  
  
  testoctagon <- data.frame(x=cos( 2*seq(1:8)*pi/8 ), y= sin(2*seq(1:8)*pi/8))
  
  expect_equal(calcArea(testoctagon) , 2.828, tolerance=0.01)
})

test_that("Angle calculation works", {
  
  horizontal <- data.frame(p1x= 10, p1y = 10, p2x = 20, p2y = 10)
  expect_equal(calcAngleRowWise(horizontal, c(1,2)), 0)
  
  # Line going right to left
  horizrev <- data.frame(p1x= 20, p1y = 10, p2x = 10, p2y = 10)
  expect_equal(calcAngleRowWise(horizrev, c(1,2)), pi)
  
  
  vertical <- data.frame(p1x = 10, p1y = 10, p2x = 10, p2y = 20)
  expect_equal(calcAngleRowWise(vertical, c(1,2)), pi/2)
  
  verticalrev <- data.frame(p1x = 10, p1y = 20, p2x = 10, p2y = 10)
  expect_equal(calcAngleRowWise(verticalrev, c(1,2)), -pi/2)
  
  # Would have been easier to do this
  expect_equal(calcAngleRowWise(vertical, c(1,2)), 
               -calcAngleRowWise(vertical, c(2,1)))
  
  diagonal <-  data.frame(p1x = 10, p1y = 10, p2x = 20, p2y = 20)
  expect_equal(calcAngleRowWise(diagonal, c(1,2)), pi/4)

  # Doesn't make sense to define the angle if both points are the same
  expect_equal(calcAngleRowWise(diagonal, c(1,1)),NA)
    
})