mode

gistfile1.txt

Exercise: Calculating the array mode
Write a method mode which takes an Array of numbers as its input and returns an Array of the most frequent values.

If there's only one most-frequent value, it returns a single-element Array.

For example,

mode([1,2,3,3])         # => [3]
mode([4.5, 0, 0])       # => [0]
mode([1.5, -1, 1, 1.5]) # => [1.5]
mode([1,1,2,2])         # => [1,2]
mode([1,2,3])           # => [1,2,3], because all occur with equal frequency
 
def mode(array)

end

!/usr/bin/ruby

Really verbose but works.

def mode(arr)
h = {}
for i in arr
if !h.has_key?(i)
h[i] = 0
end
h[i] = h[i] + 1
end
mode = []
m = 0
for k in h.keys
if h[k] > m
m = h[k]
mode = [k]
elsif h[k] == m
mode.push(k)
end
end
puts "Mode is " + mode.to_s()
end

mode([1,2,3,3])
mode([4.5, 0, 0]) # => [0]
mode([1.5, -1, 1, 1.5]) # => [1.5]
mode([1,1,2,2]) # => [1,2]
mode([1,2,3]) # => [1,2,3], because all occur with equal frequency