tests/testthat/testsubset.R

In ffbase: Basic Statistical Functions for Package 'ff'

library(testthat)
library(ff)

context("subset")

test_that("Subsetting ff vector works",{
   x <- 1:10
   ss <- x < 5
   fx <- ff(x)
   fss <- ff(ss)
   expect_identical(subset(x, ss), subset(fx,fss)[])   
})

test_that("Subsetting ff vector with NA works correctly",{
  x <- c(7,3,NA,2)
  fx <- as.ff(x)
  
  ss <- subset(x, x < 5)
  fss <- subset(fx, fx < 5)
  
  expect_identical(fss[], ss)   
})


test_that("Subsetting ffdf works",{
  x <- iris
  fx <- as.ffdf(iris)
  
  sx <- subset(x)
  sfx <- subset(fx)
  
  expect_equivalent(sfx[,], sx)
  
  sx <- subset(x, select=Species)
  sfx <- subset(fx, select=Species)
  expect_equivalent(sfx[,,drop=FALSE], sx)
  
  sx <- subset(x, subset=Species=="setosa", select=Species)
  sfx <- subset(fx, subset=Species=="setosa", select=Species)
  expect_equivalent(sfx[,,drop=FALSE], sx)
})

test_that("Subsetting ffdf within a function works",{
  test <- function(x) {    
    a <- 1
    b <- 3
    subset(x, value > a & value < b)
  }
  m <- as.ffdf(data.frame(name = letters[1:10], value = 1:10, stringsAsFactors = TRUE))
  test(m)
})