使用awk查找列的平均值

Ben Zifkin 发表于 Dev

我是Zifkin

我正在尝试查找awk用于类的第二列数据的平均值。这是我当前的代码，其中包含我的讲师提供的框架：

#!/bin/awk

### This script currently prints the total number of rows processed.
### You must edit this script to print the average of the 2nd column
### instead of the number of rows.

# This block of code is executed for each line in the file
{
x=sum
read name
        awk 'BEGIN{sum+=$2}'
        # The script should NOT print out a value for each line
}
# The END block is processed after the last line is read
END {
        # NR is a variable equal to the number of rows in the file
        print "Average: " sum/ NR
        # Change this to print the Average instead of just the number of rows
}

我收到一条错误消息：

awk: avg.awk:11:        awk 'BEGIN{sum+=$2}' $name
awk: avg.awk:11:            ^ invalid char ''' in expression

我想我已经很近了，但是我真的不知道从这里去哪里。该代码不应太复杂，因为我们在课堂上看到的一切都是相当基本的。请告诉我。

imp25

您的特定错误与第11行有关：

awk 'BEGIN{sum+=$2}'

这是在awk哪一行被调用，并BEGIN指定了它的块-但您已经在awk脚本中，因此无需指定awk。另外，您还希望sum+=$2在输入的每一行上运行，因此不要在一个BEGIN块内运行它。因此，该行应简单地读为：

sum+=$2

您也不需要以下行：

x=sum
read name

第一个只是创建了sumnamed的同义词x，我不确定第二个是做什么的，但是都不需要。

这将使您的awk脚本：

#!/bin/awk

### This script currently prints the total number of rows processed.
### You must edit this script to print the average of the 2nd column
### instead of the number of rows.

# This block of code is executed for each line in the file
{
    sum+=$2
    # The script should NOT print out a value for each line
}
# The END block is processed after the last line is read
END {
    # NR is a variable equal to the number of rows in the file
    print "Average: " sum/ NR
    # Change this to print the Average instead of just the number of rows
}