danieleb@3: function z = l1overl2(X)
danieleb@4: %L1OVERL2 ratio between l1 and l2 norm
danieleb@3: %
danieleb@4: % USAGE
danieleb@4: % z = l1overl2(x)
danieleb@3: %
danieleb@4: % INPUT
danieleb@4: % x: input vector or matrix. If matrix, the function acts columnwise
danieleb@4: % returning one value for each column.
danieleb@3: %
danieleb@4: % OUTPUT
danieleb@4: % z: the ratio ||x||_1/||x||_2
danieleb@4: %
danieleb@4: % SEE ALSO
danieleb@4: % NORM
danieleb@4: 
danieleb@4: % Author(s): Daniele Barchiesi
danieleb@4: % Copyright QMUL
danieleb@4: % $Revision: 1
danieleb@4: 
danieleb@4: nCols = size(X,2);
danieleb@4: z = zeros(nCols,1);
danieleb@4: for i=1:nCols
danieleb@4:     z(i) = norm(X(:,i),1)/norm(X(:,i),2);
danieleb@3: end
danieleb@3: 
danieleb@3: %EOF