See this code made by @David_Tschumperle
gaussian : skip ${1=3},${2=$1},${3=0}
e[^-1] "Draw centered gaussian on image$? with standard deviations ($1,$2) and angle $3 deg."
u={cos($3*pi/180)}
v={sin($3*pi/180)}
dmax={max(w,h)}
if isnum($1) l1=$1 else l1={${1}10000*$dmax/100} fi
if isnum($2) l2=$2 else l2={${2}10000*$dmax/100} fi
l1={1/(2*max(1/3,$l1)^2)}
l2={1/(2*max(1/3,$l2)^2)}
A={$l1*$u*$u+$l2*$v*$v}
B={($l1-$l2)*$u*$v}
C={$l1*$v*$v+$l2*$u*$u}
repeat $! l[$>] nm={0,n}
w={w} h={h} ds={d},{s} rm
$w,$h,1,1,'X=x-{($w-1)/2};Y=y-{($h-1)/2};$A*X*X+2*$B*X*Y+$C*Y*Y'
* -1 exp r $w,$h,$ds
nm $nm endl done
I do not know what 11 and 12 means and why is it number.