devel/tests/test-invert.R

In Rexamine/FuzzyNumbers: Tools to Deal with Fuzzy Numbers

require("testthat")

test_that("inverting side/alpha-cut generators numerically", {

   x <- seq(0,1,by=0.001)

   fi <- approxInvert(function(x) x)
   expect_that(fi(x), equals(x))

   fi <- approxInvert(function(x) x^2)
   expect_that(fi(x), equals(sqrt(x)))

   fi <- approxInvert(function(x) x^3)
   expect_that(fi(x), equals(x^(1/3)))

   fi <- approxInvert(function(x) pbeta(x, 1, 2))
   expect_that(fi(x), equals(qbeta(x, 1, 2)))

   fi <- approxInvert(function(x) 1-pbeta(x, 1, 2))
   expect_that(fi(x), equals(qbeta(1-x, 1, 2)))

#    fi <- approxInvert(function(x) pbeta(x, 0.3, 1))
#    expect_that(fi(x), equals(qbeta(x, 0.3, 1)))
})