Research Article

Photoplethysmography Biometric Recognition Model Based on Sparse Softmax Vector and k-Nearest Neighbor

Algorithm 2

Three-layer feature extraction.
Input: Training sample X, and a testing sample y, and K-class subjects
Output:
(1) let
(2) dividing X into 4 subregions: X1, X2, X3, X4
(3) dividing y into 4 subregions: Y1, Y2, Y3, Y4
(4) for each i in {1, 2, 3, 4} do
(5)  let
(6) end for
(7) let
(8) dividing X into 16 subregions:
(9) dividing X into 16 subregions:
(10)  for each j in {1, 2, 3, … , 16} do
(11)   let
(12) end for
(13) let
(14) output