rotate screen every second

screen_rotate.sh

#!/bin/bash

while true; do
    x=$(date "+%s")
    x=$(( $x % 360 ))
    pi=`echo "4*a(1)" | bc -l`
    xrad=`echo "$x*($pi/180)" | bc -l`
    sinx=`echo "s($xrad)" | bc -l`
    sinx2=`echo "- s($xrad)" | bc -l`
    cosx=`echo "c($xrad)" | bc -l`
    xrandr --output VGA1 --transform $cosx,$sinx2,0,$sinx,$cosx,0,0,0,1
    sleep 1
done