%!

/e 2.71828 def
/pi 3.141593 def
% z = [x y] -> e^z + z

/expn {
1 dict begin
aload pop
/y exch def
/x exch def
[ 
  e x exp y 180 mul pi div cos mul x add 
  e x exp y 180 mul pi div sin mul y add
] 
end
} def

% ------------------------------------------------------------

2.25 72 mul 5.5 72 mul translate

/S 36 def
S dup scale
1 S div setlinewidth

/llx -2 def
/lly -1 def
/urx 2 def
/ury 1 def
/M 20 def
/N 10 def
/dx urx llx sub M div def
/dy ury lly sub N div def

newpath
0 1 M { /i exch def
0 1 N { /j exch def
[ llx dx i mul add
 lly dy j mul add ]
expn 
aload pop

j 0 eq {
  moveto
}{
  lineto
} ifelse

} for
} for
stroke

newpath
0 1 N { /j exch def
0 1 M { /i exch def
[ llx dx i mul add
 lly dy j mul add ]
expn
aload pop

i 0 eq {
  moveto
}{
  lineto
} ifelse

} for
} for
stroke