benford_signif_patch.R

test_x = runif(10000, min = 0, 1000)
test_x = test_x * 1e+10

orig_signif = function(x, digits = 1) {
  xx = abs(x);
  return(trunc((10^((floor(log10(x)) * -1) + digits - 1)) * x))
}

new_signif = function(x, digits = 1) {
  xx = abs(x);
  return(trunc(exp(log(10)*(-floor((log(xx)/log(10))) + digits - 1) + log(xx))))
}

# Yikes!
BenfordTests::signifd(100000000000)
#[1] 0
orig_signif(100000000000)
#[1] 0
# Good!
new_signif(100000000000)
#[1] 1

orig_x = orig_signif(test_x)
new_x = new_signif(test_x)
all(orig_x == new_x)

orig_x = orig_signif(test_x, 2)
new_x = new_signif(test_x, 2)
all(orig_x == new_x)

orig_x = orig_signif(test_x, 3)
new_x = new_signif(test_x, 3)
all(orig_x == new_x)

# patch
signifd = function(x = NULL, digits = 1) {
    if (!is.numeric(x)) {
        stop("x needs to be numeric.")
    }
    x <- abs(x)
    return(trunc(exp(log(10)*(-floor((log(xx)/log(10))) + digits - 1) + log(xx))))
}