Special Code: Stencil Index   <<   >>
 

  {⊢⍵}      {,⍵}      {⊂⍵}

  {+/,⍵}
  {∧/,⍵}    {∨/,⍵}    {=/,⍵}    {≠/,⍵}
        
  {  +/,A×⍵}    {  +/⍪A×⍤2⊢⍵}
  {C<+/,A×⍵}    {C<+/⍪A×⍤2⊢⍵}

C:   a single number or a variable whose value is a single number
A:   a variable whose value is a rank-2 or -3 array

The comparison can be < ≤ ≥ > = ≠

odd window size; movement 1; matrix argument


   b←1=?100 160⍴2

   cmpx '{ +/,⍵}⌺3 5 ⊢b' '{⊢+/,⍵}⌺3 5 ⊢b'
  { +/,⍵}⌺3 5 ⊢b → 3.13E¯5 |       0%
  {⊢+/,⍵}⌺3 5 ⊢b → 4.29E¯2 | +137150% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕