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#!/usr/bin/env ruby
aspirin_total = 11037
aspirin_heart = 104
aspirin_pop = ([0]*(aspirin_total-aspirin_heart) + [1.0]*aspirin_heart).shuffle
placebo_total = 11034
placebo_heart = 189
placebo_pop = ([0]*(placebo_total-placebo_heart) + [1.0]*placebo_heart).shuffle
def sample a, n
sample = []
n.times {
sample << a[rand(n)]
}
return sample
end
ratios = []
(0).upto(100000) {
aspirin_sample = sample(aspirin_pop, aspirin_total)
placebo_sample = sample(placebo_pop, placebo_total)
r = aspirin_sample.inject(:+) / placebo_sample.inject(:+)
ratios << r
}
ratios.sort!
mean = ratios.inject(:+)/ratios.size
var = 0
ratios.each { |r|
var += (mean - r)**2
}
stddev = Math.sqrt(var/ratios.size)
puts "mean = %f"%mean
puts "stddev = %f"%stddev
_25th = ratios[0,0.25*ratios.size]
puts "25th = %f"%(_25th.inject(:+)/_25th.size)
_975th = ratios[0.975*ratios.size, ratios.size]
puts "975th = %f"%(_975th.inject(:+)/_975th.size)
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