2

我编写了一个程序，您可以在其中找到存储在另一个 txt 文件中的数据的平均值和标准差。但是，每当我运行它时，我都会收到一条错误消息，指出它无法将浮点数转换为数组：

avg_temp.rb:27:in `-': can't convert Float into Array (TypeError)
    from avg_temp.rb:27:in `block in <main>'
    from avg_temp.rb:26:in `each'
    from avg_temp.rb:26:in `<main>'

这是行：

variance = variance + (x-avg)**2

这是程序：

data = File.open("avg_temp.txt", "r+")

contents = data.read

contents = contents.split("\r\n")
#split up array
contents.collect! do |x|
        x.split(',')
end


sum = 0

contents.each do |x|
#make loop to find average
        sum = sum  + x[1].to_f 
end
avg = sum / contents.length
puts "The average temperature of Laguardia Airport from 11/97 - 05/11 is:
#{ avg.round(3)}C (Answer is rounded to nearest thousandth place)"
#puts average


variance = 0
contents.each do |x|
        variance = variance + (x-avg)**2
end 

variance = variance / contents.length
variance = Math.sqrt(variance)
puts variance
4

1 回答 1

1

由于您的平均值仅基于x[1]，因此我假设这些值很重要。在这种情况下，只需x[1].to_f像对总和一样使用：

variance = variance + (x[1].to_f - avg)**2
于 2013-10-21T20:28:02.173 回答