changeset 16:d42c500b8ad0

Add non-convolutional version

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/notes/hnmf.m	Wed Mar 26 08:33:45 2014 +0000
@@ -0,0 +1,114 @@
+function [w,h,z,xa] = hnmf( x, K, R, iter, sh, sz, w, h, pl, lh, lz)
+% function [w,h,z,xa] = hnmf( x, K, R, iter, sh, sz, w, h, pl, lh, lz)
+%
+% Perform Multi-source NMF
+%
+% Inputs:
+%  x     input distribution
+%  K     number of components
+%  R     number of sources
+%  iter  number of EM iterations [default = 100]
+%  sh    sparsity of h
+%  sz    sparsity of z
+%  w     initial value of w
+%  h     initial value of h
+%  pl    plot flag
+%  lh    update h flag
+%  lz    update z flag
+%
+% Outputs:
+%  w   spectral bases
+%  h   component activation
+%  z   source activation per component
+%  xa  approximation of input
+%
+% Emmanouil Benetos 2011
+
+
+% Get sizes
+[M,N] = size( x);
+sumx = sum(x);
+
+% Default training iterations
+if ~exist( 'iter')
+    iter = 100;
+end
+
+% Default plot flag
+if ~exist( 'pl')
+    pl = 1;
+end
+
+% Initialize
+if ~exist( 'w') || isempty( w)
+    w = rand( M, R, K);
+end
+for r=1:R
+    for k=1:K
+        w(:,k,r) = w(:,k,r) ./ sum(w(:,k,r));
+    end;
+end;
+if ~exist( 'h') || isempty( h)
+    h = rand( K, N);
+end
+n=1:N;
+h(:,n) = repmat(sumx(n),K,1) .* (h(:,n) ./ repmat( sum( h(:,n), 1), K, 1));
+if ~exist( 'z') || isempty( z)
+    z = rand( R, K, N);
+end
+for k=1:K
+    for n=1:N
+        z(:,k,n) = z(:,k,n) ./ sum(z(:,k,n));
+    end;
+end;
+
+
+
+% Iterate
+for it = 1:iter
+    
+    % E-step
+    zh = z .* permute(repmat(h,[1 1 R]),[3 1 2]);
+    xa=eps;
+    for r=1:R
+        for k=1:K
+            xa = xa + w(:,k,r) * squeeze(zh(r,k,:))';
+        end; 
+    end;
+    Q = x ./ xa;
+    
+    % M-step (update h,z)
+    if  (lh && lz)
+        nh=zeros(K,N);
+        for k=1:K
+            for r=1:R
+                nh(k,:) = nh(k,:) + squeeze(z(r,k,:))' .* (squeeze(w(:,k,r))' * Q);
+                nz = h(k,:) .* (squeeze(w(:,k,r))' * Q);
+                nz = nz .* squeeze(z(r,k,:))';
+                z(r,k,:) = nz;
+            end;
+        end;
+        nh = h .* nh;
+    end
+    
+    
+    % Assign and normalize
+    k=1:K;
+    n=1:N;
+    if lh
+        nh = nh.^sh;
+        h(:,n) = repmat(sumx(n),K,1) .* (nh(:,n) ./ repmat( sum( nh(:,n), 1), K, 1));
+    end
+    if lz
+        z = z.^sz;
+        z(:,k,n) = z(:,k,n) ./ repmat( sum( z(:,k,n), 1), R, 1);
+    end
+    
+end
+
+% Show me
+if pl
+    subplot(3, 1, 1), imagesc(x), axis xy
+    subplot(3, 1, 2), imagesc(xa), axis xy
+    subplot(3, 1, 3), imagesc(h), axis xy
+end