tt←?1e6 2⍴100
   tt[;0]←1e6⍴'abc'
   ii←invert tt

   cmpx '50>1⊃ii' '50>tt[;1]'
50>1⊃ii   → 9.61E¯4 |     0% ⎕⎕
50>tt[;1] → 1.42E¯2 | +1376% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕

   1.42e¯2 ÷ 9.61e¯4
14.7763

   ⎕size 'tt' 'ii'
80000040 2000112
   ÷/ ⎕size 'tt' 'ii'
39.9978