samer@4: function l=alpha_norm(alpha,x)
samer@4: % alpha_norm - Minkowski norm (actually more like mean) using given exponent
samer@4: %
samer@4: % alpha_norm :: nonneg ~'exponent', [[N,M]] -> [[1,M]->nonneg].
samer@4: % alpha_norm :: nonneg ~'exponent', [[1,N]] -> nonneg.
samer@4: %
samer@4: % This version divides by the dimemnsionality of the space,
samer@4: % eg
samer@4: %    alpha_norm(2,x) = sqrt(mean(x.^2,1))
samer@4: %    alpha_norm(1,x) = mean(abs(x),1))
samer@4: l=real(mean(abs(x).^alpha).^(1/alpha));                                
samer@4: