function y = testfun( x )
% TESTFUN The name says it all

[m,num_samples] = size( x );

y = [ 1:num_samples ];   % preallocate
for loc = 1:num_samples
	if x( loc ) > 0 
		y( loc ) = 1;
	else
		y( loc ) = 0;
	end
end