tests/testthat/test-expand-grid.R

In RxODE: Facilities for Simulating from ODE-Based Models

rxodeTest(
  {
    expand.grid.jc <- function(seq1, seq2) {
      cbind(
        Var1 = rep.int(seq1, length(seq2)),
        Var2 = rep.int(seq2, rep.int(length(seq1), length(seq2)))
      )
    }

    x <- microbenchmark::microbenchmark(rxExpandGrid(letters, letters), expand.grid.jc(letters, letters))

    library(dplyr)

    x <- as.data.frame(x) %>%
      group_by(expr) %>%
      summarize(x = median(time)) %>%
      arrange(expr)

    ## context("Faster Expand Grid")
    ## test_that("rxExpandGrid is faster that expand.grid.jc", {
    ##     expect_true(x$x[1] < x$x[2]);
    ## })

    f <- function() {
      tmp <- setNames(data.frame(expand.grid.jc(letters, letters),
        stringsAsFactors = FALSE
      ), c("s1", "s2"))
      tmp <- cbind(tmp, with(tmp, data.frame(
        rx = paste0("df(", s1, ")/dy(", s1, ")"),
        sym = paste0("__d_df_", s1, "_dy_", s2, "__"),
        line = paste0("__d_df_", s1, "_dy_", s2, "__=diff(rx__d_dt_", s1, "__, ", s2, ")")
      )))
      return(tmp)
    }

    x <- microbenchmark::microbenchmark(
      rxExpandGrid(letters, letters, 1L),
      f()
    )

    x <- as.data.frame(x) %>%
      group_by(expr) %>%
      summarize(x = median(time)) %>%
      arrange(expr)

    test_that("rxExpandGrid is faster than printing out letters", {
      expect_true(x$x[1] < x$x[2])
    })
  },
  test = "lvl2"
)