[ NaN, NaN],
[ NaN, NaN]])
>>> retract[1097:1103,-2:] # doctest: +ELLIPSIS
-Data([[ NaN, 5.234...e-10],
- [ NaN, 5.612...e-10],
- [ NaN, 6.132...e-10],
- [ NaN, 6.292...e-10],
- [ NaN, 7.105...e-10],
+Data([[ NaN, 5.2...e-10],
+ [ NaN, 5...e-10],
+ [ NaN, 6.1...e-10],
+ [ NaN, 6.2...e-10],
+ [ NaN, 7...e-10],
[ NaN, NaN]])
>>> retract[-5:,-2:]
Data([[ NaN, NaN],