I wrote a func to calculcate integers difference in csv.

getSegLatency() {
latencies=0$1
E2E=0`echo $2 | sed 's/\.000000//g'`
integer segLatency=0
set -A arr `echo $latencies | sed 's/\.000000//g' | sed 's/,/ /g'`
res=${arr[0]}
integer i=1
while ((i < ${#arr[*]})); do
((segLatency=${arr[$i]} - ${arr[$i - 1]}));
res="$res,$segLatency"
(( i = i + 1));
done
((segLatency=$E2E - ${arr[$i - 1]}));
res="$res,$segLatency"
echo $res
}

in which the number of elements in $1 may vary
e.g. when i call like:
getSegLatency 1.000000,4.000000,6.000000,7.000000 11.000000
i'll get:
3,2,1,4

It works well but the performance is slow.

Is there any way to polish the script to run faster?