Assertions#assert_in_delta

require "test/unit"
include Test::Unit::Assertions
begin
  assert_in_delta -39.30 * 100, -3930, 1e-12 #in 1e-12
rescue
    print "not in 1e-12", "/n"
else
    print "in 1e-12", "/n"
end
begin
  assert_in_delta -39.30 * 100, -3930, 1e-13 #not in 1e-12
rescue
    print "not in 1e-13", "/n"
else
    print "in 1e-13", "/n"
end