Algorithm 3.

Acquisition of adjacency matrix A_i.

Step 1: Initialization (See Eqs. (7)-10)

Initialize adjacency matrix Ai;

Initialize distance between features Distance;

Initialize variable Sorted_Distance for sorted distance;

Initialize variable Index;

Step 2: Distance calculation

for a = 1:S

for b = 1:S

if a!=b

$\mathit{Distance}\left(\mathit{a},\mathit{b}\right)=\text{sum}\left({\mathit{f}}_{\mathit{a}}-{\mathit{f}}_{\mathit{b}}\right)$;

end

end

end

Step 3: Output Ai

for a = 1:S

$\left[\mathit{Sorted}\_\mathit{Distance}\left(\mathit{a},:\right),\mathit{Index}\left(\mathit{a},:\right)\right]=\text{sort}\left(\mathit{Distance}\left(\mathit{a},:\right)\right)$;

for c = 1:k

${\mathit{A}}_{\mathit{i}}\left(\mathit{a},\mathit{Index}\left(\mathit{a},\mathit{c}\right)\right)=1$;

end

end

then output Ai.