Average integer elements in array
USAGE: mean arrayname varname
mean()
{
local arrayname=${1:?Array name required} varname=${2:-var}
local total=0 v n=0
Copy the array, $arrayname, to local array
eval "array=( \"\${$arrayname[@]}\" )"
for v in "${array[@]}"
do
case $v in *[!0-9-]*) continue ;; esac
total=$(( total + v ))
n=$(( n + 1 ))
done
printf -v "$varname" "%d" "$(( total / n ))"
}