Method on @infsup: sign (X)

Compute the signum function for each number in interval X.

Accuracy: The result is a tight enclosure.

sign (infsup (2, 3))
  ⇒ ans = [1]
sign (infsup (0, 5))
  ⇒ ans = [0, 1]
sign (infsup (-17))
  ⇒ ans = [-1]

Package: interval