quantity.Discrete.compose: some clean-up & readability

+quantity/Discrete.m

@@ -251,18 +251,18 @@ classdef  (InferiorClasses = {?quantity.Symbolic}) Discrete ...
 			h = misc.hash(data);
 		end % hash()
 		
-		function d = compositionDomain(obj, domainName)
-			
-			assert(isscalar(obj));
-					
-			d = obj.on();
+		function thisDomain = compositionDomain(obj, domainName)
+			% compositionDomain is a helper function for compose.
+			arguments
+				obj (1, 1) quantity.Discrete;
+				domainName (1, 1) string;
+			end
 			
-			% the evaluation of obj.on( compositionDomain ) is done by:
-			d_size = size(d);
+			dDiscrete = obj.on();
 			
 			% vectorization of the n-d-grid: compositionDomain	
-			d = quantity.Domain(domainName, d(:));
-		end
+			thisDomain = quantity.Domain(domainName, dDiscrete(:));
+		end % compositionDomain
 		
 		function obj_hat = compose(obj, g, optionalArgs)
 			% COMPOSE compose two functions
@@ -272,41 +272,35 @@ classdef  (InferiorClasses = {?quantity.Symbolic}) Discrete ...
 			%	if f(t) = obj, g is G and f_hat is OBJ_hat.
 			arguments
 				obj
-				g quantity.Discrete;
-				optionalArgs.domain quantity.Domain = obj(1).domain;
+				g (1, 1) quantity.Discrete;
+				optionalArgs.domain (1, 1) quantity.Domain = obj(1).domain(1);
 			end
-			myCompositionDomain = optionalArgs.domain;
-			originalDomain = obj(1).domain;
 			
 			% quick workaround to apply to marix valued quantities
 			if numel(obj) > 1
+				obj_hat = copy(obj);
 				optArgs = misc.struct2namevaluepair( optionalArgs );
 				for k = 1:numel(obj)
 					obj_hat(k) = compose(obj(k), g, optArgs{:});
 				end
-				obj_hat = reshape(obj_hat, size(obj));
 				return
 			end
 			
-			assert( length( myCompositionDomain ) == 1 );
+			myCompositionDomain = optionalArgs.domain;
+			originalDomain = obj(1).domain;
 			[idx, logOfDomain] = originalDomain.index(myCompositionDomain);
-			assert( isequal( originalDomain(idx), myCompositionDomain ), ...
-				'Composition of functions: The domains for the composition must be equal. A grid join is not implemented yet.');
-			assert( any( logOfDomain )  )
 			
 			% get the composition domain:
-			%	For the argument y of a function f(y) which should be
-			%	composed by y = g(z,t) a new dommain will be created on the
-			%	basis of evaluation of g(z,t).
-			composeOnDomain = ...
-				g.compositionDomain(myCompositionDomain.name);
-			
-			% check if the composition domain is in the range of definition
-			% of obj.
-			if ~composeOnDomain.isSubDomainOf( myCompositionDomain )
+			%	For the argument y of a function f(y), which should be
+			%	composed by y = g(z,t), a new domain is created by evaluating g(z,t).
+			composeOnDomain = g.compositionDomain(myCompositionDomain.name);
+			
+			% check if the composition domain is in the range of definition of obj.domain.
+			if ~composeOnDomain.isSubDomainOf( originalDomain(idx) )
 				warning('quantity:Discrete:compose', ....
-					'The composition domain is not a subset of obj.domain! The missing values will be extrapolated.');
-			end			
+					"The composition domain is not a subset of obj.domain, i.e. the values of g " ...
+					+ "exceed the grid of obj.domain. Missing values will be extrapolated.");
+			end
 			
 			% evaluation on the new grid:
 			%	the order of the domains is important. At first, the
@@ -317,9 +311,8 @@ classdef  (InferiorClasses = {?quantity.Symbolic}) Discrete ...
 			%	g(z,t)
 			
 			% #TODO: optimize the memory consumption of this function.
-			%	1) only consider the unqiue grid points in evaluationDomain
-			%	2) do the conversion of the evaluationDomain directly to
-			%	the target domain.			
+			%	1) only consider the unique grid points in evaluationDomain
+			%	2) do the conversion of the evaluationDomain directly to the target domain.			
 			evaluationDomain = [originalDomain( ~logOfDomain ), composeOnDomain ];
 			
 			newValues = obj.on( evaluationDomain );
@@ -328,7 +321,7 @@ classdef  (InferiorClasses = {?quantity.Symbolic}) Discrete ...
 			% dimension is any domain but the composition domain and the
 			% last dimension is the composition domain
 			sizeOldDomain = prod( [originalDomain( ~logOfDomain ).n] );
-			sizeComposeDomain = composeOnDomain.gridLength;
+			sizeComposeDomain = composeOnDomain.n;
 			newValues = reshape(newValues, [sizeOldDomain, sizeComposeDomain]);
 
 			%rearrange the computed values, to have the same dimension
@@ -356,9 +349,7 @@ classdef  (InferiorClasses = {?quantity.Symbolic}) Discrete ...
 			end
 			
 			if ~isempty(intersectDomain)
-				
 				idx = tmpDomain.index( intersectDomain );
-				
 				% take the diagonal values of the common domain, i.e., z = zeta		
 				% use the diag_nd function because it seems to be faster
 				% then the diagNd function, although the values must be
@@ -368,7 +359,7 @@ classdef  (InferiorClasses = {?quantity.Symbolic}) Discrete ...
 			
 			% *) build a new valueDiscrete on the correct grid.		
 			obj_hat = quantity.Discrete( newValues, tmpDomain.join, ...
-				'name', obj.name + " ° " + g.name);
+				"name", obj.name + " ° " + g.name);
 			
 		end % compose()