ruby - Do average on hashes -

lets got 3 hashes:

hash1={ => 1, b => 2, c => 4 }   hash2={ b => 1, c => 3 }  hash3={ => 2, b => 1, c => 3, d => 4 } 

i want average stuff new hash according keys, new hash be

result={a=>1.5,b=>4/3,c=>10/3,d=>4} 

meaning if key not exists in 1 hash don't count 0.

is there elegant way?

result = {} [hash1, hash2, hash3].each{|h| h.each{|k, v| (result[k] ||= []).push(v)}} result.each{|k, v| result[k] = v.inject(:+).to_f/v.length} result # => # { #   => 1.5, #   b => 1.3333333333333333, #   c => 3.3333333333333335, #   d => 4.0 # }