samer@4: function M=intmap(min,max)
samer@4: % intmap - Discretisation map for integers (ie alread discrete)
samer@4: %
samer@4: % intmap :: integer~'min value', integer~'max value' -> dmap(N).
samer@4: %
samer@4: % Maps integers to natural numbers, saves on multiplications and
samer@4: % roundings as performed by the real->natural maps.
samer@4: 
samer@4: 	N=max-min+1;
samer@4: 	off=min-1;
samer@4: 	M=dmap(N,@map,@revmap);
samer@4: 
samer@4: 	function I=map(X)
samer@4: 		I=X-off;
samer@4: 		I(I<1)=-inf;
samer@4: 		I(I>N)=inf;
samer@4: 	end
samer@4: 
samer@4: 	function X=revmap(I)
samer@4: 		I=shiftdim(shiftdim(I),-1);
samer@4: 		X1=off+I-0.5;
samer@4: 		X2=off+I+0.5;
samer@4: 		X=cat(1,X1,X2);
samer@4: 	end
samer@4: end
samer@4: