Question

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，有时我运行它会得到一个错误，说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>'

这是一行：

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

这是该计划：

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

Answer 1

由于您的平均值仅基于x[1]，因此我认为这些值非常重要。在这种情况下，只需使用x[1].to_f，就像你所做的那样：

variance = variance + (x[1].to_f - avg)**2

如何将浮点数转换为ruby中的数组？

1 个答案: