create random Dates, POSIX dates, letters and numbers. The numbers explore limits of R precision and floating point and integer ranges. Zero, negatives, positives.
random_test_numbers(n = n_rnd, min = NULL, max = NULL, hole = NULL)random_test_integers(n = n_rnd, min = -.Machine$integer.max,
max = .Machine$integer.max, hole = NULL)
random_test_letters(n = n_rnd, max_str_len = 257)
integer number of each group to generate
optional minimum number
optional maximum number
is a closed range of numbers not to include, e.g. c(1,2) would discard 1, 1.1 pi/2 and 2
integer scalar, maximum length of possible strings
created, as distinct from number of strings given by n
vector length 5n+1 containing variety of difficult numbers for testing purposes