It Takes a Whole Life to be Arrix

We want to fetch an avatar of specific size. How to find the closest size from all available sizes? Suppose available sizes are 16, 48 and 96.

An obvious version is

 def closest_size(size)
 case
 when size < 32
 16
 when size < 72
 48
 else
 96
 end
 end

The value used in comparison tests is the average of two neighboring candidate sizes. The problem is that when our available sizes change, we need to add or remove when clauses and recalculate average values.

Here is a smarter way

def closest_size(size)
 points = [16, 48, 96]
 distances = points.map {|a| (size - a).abs}
 points[distances.index(distances.min)]
end

It finds the point with shortest distance to the given size. Now if we want to change candidate sizes, we only need to change the array literal. Further, we can even pass the candidate array as an argument.

Posted by Arrix at 1:15 PM 4 comments

Labels: clog, ruby, tip