require 'fileutils'
FileUtils.mkdir_p 'tmp'
Dir.foreach(".") do |filename|
    next unless filename =~ /^\d+?.csv$/i
    
    in_lines = IO.readlines(filename)
    delta = nil
    in_lines[4].scan(/^Delta\(second\),(.*?)\r\n$/) do |matched|
        delta = matched[0].to_f
    end
    in_lines = in_lines[43..-1] #42行目までを捨てる
    
    base = File.basename(filename.downcase, ".csv")
    open("tmp/#{base}.csv", "w") do |out_file|
        out_file.puts "#t, ch1, ch2"
        in_lines.size.times do |i|
            in_lines[i].scan(/^(.*?),(.*?)\r\n$/) do |matched|
                ch1 = matched[0].to_f
                ch2 = matched[1].to_f
                out_file.puts "#{i*delta}, #{ch1}, #{ch2}"
            end
        end
    end
end