x=$='*~(15-:%)%_ -- list of x coord of "*"s
y=$='*~(15-:)%_- -- list of y coord ditto
f=x*M/(y|~-y)`(y~) -- order
r="(" x ", " y ")" % -- format
f!r -- sort
Note that non-ascii characters in the above source code will be escaped (such as \x9f).