bash- find average of numbers in line

Question

I am trying to read a file line by line and find the average of the numbers in each line. I am getting the error: expr: non-numeric argument

I have narrowe

Answer 1

This is a pretty old post, but came up at the top my Google search, so thought I'd share what I came up with:

while read line; do
    # Convert each line to an array
    ARR=( $line )

    # Append each value in the array with a '+' and calculate the sum
    #   (this causes the last value to have a trailing '+', so it is added to '0')
    ARR_SUM=$( echo "${ARR[@]/%/+} 0" | bc -l)

    # Divide the sum by the total number of elements in the array
    echo "$(( ${ARR_SUM} / ${#ARR[@]} ))"
done < "$filename"