tests/testthat/testthat_comparisonsDVR.R

In droglenc/FSAmisc: Miscellaneous functions for simple fisheries stock assessment methods

## Prepare data for testing
data(Mirex,package="FSA")
Mirex$fyear <- factor(Mirex$year)


## Test Messages ----
test_that("compSlopes() & compIntercepts() mesages",{
  ## Model not a DVR/IVR
  # SLR
  tmp <- lm(mirex~weight,data=Mirex)
  expect_error(compSlopes(tmp),
               "only works for dummy")
  expect_error(compIntercepts(tmp),
               "only works for dummy")
  # 1-way ANOVA
  tmp <- lm(mirex~fyear,data=Mirex)
  expect_error(compSlopes(tmp),
               "only works for dummy")
  expect_error(compIntercepts(tmp),
               "only works for dummy")
  # 2-way ANOVA
  tmp <- lm(mirex~fyear*species,data=Mirex)
  expect_error(compSlopes(tmp),
               "only works for dummy")
  expect_error(compIntercepts(tmp),
               "only works for dummy")
  # multiple linear regression (not DVR/IVR)
  tmp <- lm(mirex~year+weight,data=Mirex)
  expect_error(compSlopes(tmp),
               "only works for dummy")
  expect_error(compIntercepts(tmp),
               "only works for dummy")
  # 2-way IVR/DVR
  tmp <- lm(mirex~weight*year*species,data=Mirex)
  expect_error(compSlopes(tmp),
               "with one factor and one covariate")
  expect_error(compIntercepts(tmp),
               "with one factor and one covariate")

  ## Testing intercepts with an interaction in the model
  tmp <- lm(mirex~weight*fyear,data=Mirex)
  expect_warning(compIntercepts(tmp),
                 "Removed an interaction")

  ## Only two groups/levels ... function not needed
  Mirex2 <- filterD(Mirex,year %in% c(1977,1982))
  tmp <- lm(mirex~weight*fyear,data=Mirex2)
  expect_warning(compSlopes(tmp),
                 "Function not needed with fewer than three levels")
  expect_warning(compIntercepts(tmp),
                 "Function not needed with fewer than three levels")
})


## Test Output Types ----
test_that("Same results with compSlopes() & compIntercepts() if variables are reversed",{
  tmp1 <- lm(mirex~weight*fyear,data=Mirex)
  tmp2 <- lm(mirex~fyear*weight,data=Mirex)
  expect_identical(compSlopes(tmp1),compSlopes(tmp2))
  expect_identical(suppressWarnings(compIntercepts(tmp1)),
                   suppressWarnings(compIntercepts(tmp2)))
})

## Validate Results ----