32651:ERROR comparison of Float with Float failed ruby - ruby-on-rails

Question

I'm new to rails, and I'm getting an error and I can't seem to find were the problem is. Here is the log:
[32651:ERROR] 2012-10-09 13:46:52 :: comparison of Float with Float failed
[32651:ERROR] 2012-10-09 13:46:52 :: /home/sunny/backend/lib/analytics/lifetime.rb:45:in `each'
/home/sunny/backend/lib/analytics/lifetime.rb:45:in `max'
/home/sunny/backend/lib/analytics/lifetime.rb:45:in `max_growth'
/home/sunny/backend/lib/analytics/lifetime.rb:15:in `run'
/home/sunny/backend/lib/analytics/post_analytics.rb:102:in `lifetime'
/home/sunny/backend/lib/analytics/post_analytics.rb:27:in `run`run'
lib/endpoints/posts/index.rb:65:in `block in response'
lib/endpoints/posts/index.rb:62:in `each'
lib/endpoints/posts/index.rb:62:in `response'
/usr/local/lib/ruby/gems/1.9.1/gems/goliath-1.0.0.beta.1/lib/goliath/api.rb:163:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/goliath-1.0.0.beta.1/lib/goliath/rack/validation/required_param.rb:43:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/goliath-1.0.0.beta.1/lib/goliath/rack/params.rb:61:in `block in call'
/usr/local/lib/ruby/gems/1.9.1/gems/goliath-1.0.0.beta.1/lib/goliath/rack/validator.rb:40:in `safely'
/usr/local/lib/ruby/gems/1.9.1/gems/goliath-1.0.0.beta.1/lib/goliath/rack/params.rb:59:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/goliath-1.0.0.beta.1/lib/goliath/rack/async_middleware.rb:73:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.4.1/lib/rack/content_length.rb:14:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/async-rack-0.5.1/lib/async_rack/async_callback.rb:114:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/async-rack-0.5.1/lib/async_rack/async_callback.rb:91:in `block in new'
/usr/local/lib/ruby/gems/1.9.1/gems/goliath-1.0.0.beta.1/lib/goliath/request.rb:163:in `call'
/usr/local/lib/ruby/gems/1.9.1/gems/goliath-1.0.0.beta.1/lib/goliath/request.rb:163:in `block in process'
Whenever I go to the file and find that row, there is no each, and I can't understand where the problem is. Can anyone help? More than a fix, I want to understand the problem.
Here is the file:
class Lifetime
attr_reader :values
GROWTH_CUT_OFF = 0.10
def initialize(engaged_users_values)
#values = engaged_users_values
end
def run
growths = growth(values)
return [0] if growths.uniq.first == 0 || growths.empty?
max_growth = max_growth(growths)
dead_growth = least_growth(growths, max_growth)
time_diff = time_diff(values.last['end_time'],
values.first['end_time'])
return [time_diff] unless dead_growth
dead_loc = growths.index(dead_growth)
dead_value = values[dead_loc]
lifetime(values.first, dead_value)
end
def time_diff(last, first)
in_minutes(parse_time(last)-parse_time(first))
end
def parse_time(time)
DateTime.parse(time)
end
def growth(values)
values.each_cons(2).map do |one, two|
one_value = one['value'].to_f
two_value = two['value']
((two_value-one_value)/(one_value)*100).round(2)
end
end
def max_growth(growths)
growths.max
end
def least_growth(growths, max_growth)
growth_cut = growth_cut(max_growth)
growths.select {|g| g <= growth_cut}.first
end
def growth_cut(max_growth)
max_growth*GROWTH_CUT_OFF
end
def lifetime(first_value, last_value)
first = parse_time(first_value['end_time'])
last = parse_time(last_value['end_time'])
result = last-first
[in_minutes(result)]
end
def in_minutes(time)
time.to_f*24*60
end
end

Answer 1

If one of both Floats is NaN then you get this message. So, prevent the NaN case.
We can give you more info if you post the exact code of the error (the max_growth method)