A predicate method to tell if a number is near another
near? like the following would be useful.
class Numeric def near? other, delta: Float::EPSILON (other.to_f - to_f).abs <= delta.to_f end end class Time def near? other, delta: Float::EPSILON to_f.near?(other.to_f, delta: delta) end end
It can be used to check errors, or whether something is around something.
23.24324.near?(23.23, delta: 0.5) # => true t1 = t2 = Time.now t3 = Time.now t1.near?(t2) #=> true t1.near?(t3) #=> false 5.near?(3, delta: 1) #=> true
Some testing frameworks have something similar to this, but I think this is an elementary concept that Ruby should support at it core.
Updated by sawa (Tsuyoshi Sawada) almost 5 years ago
The definition above is just to illustrate the functions. There may be a better implementation. Especially, an appropriate error message should be given when an inappropriate argument is given.
error might be a better name to replace the named parameter
delta. I am not sure.