PeakElement←{
⍝ ⍵: Array
⍝ A peak cell is a cell which grades higher than its neighbours
     1=≢⍵:⍵
     FPMC←{3=2⌷⍋⍋⍵} ⍝ Find Peak Major Cell in group of 3
     ⍵⌿⍨FPMC⌺3⊢⍵
 }