Ruby's floating point errors

ruby_floating_point_errors.rb

# Ruby's floating point errors
# "Sometimes it's easier avoiding a problem than solving it."
0.2 > (1.to_r/5)       # false
0.2.to_r == 0.2        # true
0.2.to_r > (1.to_r/5)  # true

# There is a certain range of floating point calculation errors, which is ignored.
0.2.to_r               # (3602879701896397/18014398509481984)
0.2.to_r - (1.to_r/5)  # (1/90071992547409920)   (it should be 0)

# The (sometimes) ignored floating point error is (1/90071992547409920).
# Yes it's very small, but it's still there.
# To avoid these kind of errors, don't use floats.