#!/usr/bin/ruby

if ARGV.size < 2 then
  puts "Usage: #{__FILE__} (log_AD_calib_CSV1) (log_AD_calib_CSV2)"
  exit
end

# logの形式は1行に[line_no, gps_time, accel(3), gyro(3), temperature]
def log_read(b)
  eval %Q{
    i = 0
    open(log_file).each{|line|
      if (i += 1) < 30000 then next end
      log_data << line.chop!.split(/,/).collect{|item| item.to_f}
      #if i > 35000 then break end 
    }
  }, b
end

log_file = ARGV.shift
log_data = log1_data = []
log_read(binding)

log_file = ARGV.shift
log_data = log2_data = []
log_read(binding)

#p log1_data
#p log2_data
#exit

diff_data = []

log2_item = log2_data.shift
log1_data.each{|log1_item|
  while log2_item
    #puts "#{log1_item[1]}, #{log2_item[1]}"
    if log1_item[1] == log2_item[1] then
      break
    elsif log1_item[1] < log2_item[1] then
      log1_item = nil
      break
    else
      log2_item = log2_data.shift
    end
  end
  next if log1_item == nil
  break if log2_item == nil
  
  #p log1_item, log2_item
  
  # [time, diff(accel(3), gyro(3), temp)]
  diff_data << (diff = [log1_item[1]])
  log1_item[2..-1].each_with_index{|v, i|
    diff << (v - log2_item[i + 2])
  }
  log2_item = log2_data.shift
}

if diff_data.empty? then exit end

sum = []
sum2 = []
(diff_data[0].size - 1).times{|i|
  sum << 0.0
  sum2 << 0.0
}
diff_data.each{|v|
  v[1..-1].each_with_index{|v2, i|
    sum[i] += v2
    sum2[i] += (v2 ** 2)
  }
}

#mean
mean = sum.collect{|v| v / diff_data.size}
#sigma
sigma = []
sum2.each_with_index{|v, i|
  sigma << (v / diff_data.size - (mean[i] ** 2))
}

#print
puts "index: mean, sigma"
mean.each_with_index{|v, i|
  puts "#{i}: #{v}, #{sigma[i]}"
}