Add "FAR vs PD"

2024-05-11 15:43:25 +08:00
parent 17386d80c1
commit b48ab07dd0
21 changed files with 412 additions and 0 deletions
@@ -0,0 +1,82 @@
+% Input:    y,A,lambda,tau,Kit
+% Output:   x_hat_wl,x_hat_d
+
+% Main structure of cVAMP
+function [x_hat_wl, x_hat_d] = cVAMPro(y, A, lambda, tau, Kit)
+
+    % Initialization
+    [M, N] = size(A);
+    gamma = M / N;
+    k = 0;
+    p = ctranspose(A) * y;
+    h_1 = p;
+    Q_1 = gamma;
+    tau_d = 1;
+
+    % Iteration
+    while ((k < Kit) && (tau_d > tau))
+        % Factorized Part
+        x_1 = ST(h_1, lambda, Q_1);
+        chi_1 = F1(x_1, lambda, Q_1);
+        % Message Passing
+        h_2 = x_1 / chi_1 - h_1;
+        Q_2 = 1 / chi_1 - Q_1;
+        % Gaussian Part
+        t1 = (p + h_2) / Q_2;
+        t2 = ctranspose(A) * (A * (p + h_2)) / ((Q_2 + 1) * Q_2);
+        x_2 = t1 - t2;
+        chi_2 = gamma / (Q_2 + 1) + (1 - gamma) / Q_2;
+        % Message Passing
+        h_1_next = x_2 ./ chi_2 - h_2;
+        Q_1_next = 1 / chi_2 - Q_2;
+        tau_d = norm(h_1_next - h_1, Inf) / norm(h_1_next, Inf);
+        k = k + 1;
+        % output
+        x_hat_wl = x_1;
+        x_hat_d = h_1_next / Q_1_next;
+        % next
+        h_1 = h_1_next;
+        Q_1 = Q_1_next;
+    end
+
+end
+
+% SoftThreshold function
+function x = ST(h_1, lambda, Q_1)
+    [N, M] = size(h_1);
+    x = zeros(N, M);
+
+    for i = 1:N
+        sign = h_1(i) ./ abs(h_1(i));
+        diff = abs(h_1(i)) - lambda(i);
+        x(i) = sign .* (diff ./ Q_1) .* SF(diff);
+    end
+
+end
+
+% Heaviside's step function
+function v = SF(a)
+
+    if a > 0
+        v = 1;
+    elseif a == 0
+        v = 0; % at zero points
+    else
+        v = 0;
+    end
+
+end
+
+% Calculation of chi_1
+function chi_1 = F1(x_1, lambda, Q_1)
+    [N, M] = size(x_1);
+    count = 0;
+
+    for i = 1:N
+        temp = Q_1 * abs(x_1(i)) + lambda(i);
+        count = count + (2 - lambda(i) / temp) * SF(abs(x_1(i)));
+        %         count = count + (2-lambda(i)/temp) * (abs(x_1(i)) > 1e-4);
+    end
+
+    chi_1 = count / (2 * N * Q_1);
+end