samer@4: function y=slog(x)
samer@4: % slog - safe log, x<=0 => slog(x)=0
samer@4: %
samer@4: % slog :: real -> real.
samer@4: 
samer@4: 	x(x<=0)=1;
samer@4: 	y=log(x);
samer@4: