quantity.Discrete: simple blkdiag - only works for quantities with same gridName and grid.

+quantity/Discrete.m

@@ -532,7 +532,7 @@ classdef  (InferiorClasses = {?quantity.Symbolic, ?quantity.Operator}) Discrete
 			
 			[fineGrid, fineGridName] = getFinestGrid(objCell{~isEmpty});
 			for it = 1 : (numel(varargin) + 1)  % +1 because the first entry is a
-				assert(all(strcmp(unique(fineGridName), unique(objCell{it}(1).gridName))), ...
+				assert(all(strcmp(fineGridName, objCell{it}(1).gridName)), ...
 					'gridNames of objects that are concatenated must be equal');
 				objCell{it} = objCell{it}.changeGrid(fineGrid, fineGridName);
 			end
@@ -541,6 +541,30 @@ classdef  (InferiorClasses = {?quantity.Symbolic, ?quantity.Operator}) Discrete
 			c = builtin('cat', argin{:});
 		end
 		
+		function Y = blkdiag(A, varargin)
+			% blkdiag  Block diagonal concatenation of matrix input arguments.
+			%									|A 0 .. 0|
+			% Y = blkdiag(A,B,...)  produces	|0 B .. 0|
+			%									|0 0 ..  |
+			% Yet, A, B, ... must have the same gridName and grid.
+			if nargin == 1
+				Y = copy(A);
+			else
+				B = varargin{1};
+				if isempty(B)
+					Y = A;
+				else
+					assert(isequal(A(1).gridName, B(1).gridName), 'only implemented for same grid and gridName');
+					assert(isequal(A(1).grid, B(1).grid), 'only implemented for same grid and gridName');
+					Y = [A, zeros(size(A, 1), size(B, 2)); ...
+						zeros(size(B, 1), size(A, 2)), B];
+				end
+				if nargin > 2
+					Y = blkdiag(Y, varargin{2:end});
+				end
+			end
+		end % blkdiag()
+		
 		function solution = solveAlgebraic(obj, rhs, gridName, objLimit)
 			%% this method solves
 			%	obj(gridName) == rhs

+unittests/+quantity/testDiscrete.m

@@ -4,6 +4,38 @@ function [tests] = testDiscrete()
 tests = functiontests(localfunctions);
 end
 
+function testBlkdiag(tc)
+% init some data
+syms z zeta
+t = linspace(0, 1, 25);
+A = quantity.Symbolic(...
+	[1+z*zeta, -zeta; -z, z^2], 'grid', {linspace(0, 1, 21), linspace(0, 1, 41)},...
+	'variable', {z, zeta}, 'name', 'q');
+B = 2*A(:, 1);
+C = 3*A(1);
+
+% 1 input
+tc.verifyEqual(A.on, A.blkdiag.on());
+
+% 2 x same input
+AA = blkdiag(A, A);
+tc.verifyEqual(AA(1:2, 1:2).on(), A.on());
+tc.verifyEqual(AA(3:4, 3:4).on(), A.on());
+tc.verifyEqual(AA(1:2, 3:4).on(), 0*A.on());
+tc.verifyEqual(AA(3:4, 1:2).on(), 0*A.on());
+
+% 3 different sized quantites
+ABCB = blkdiag(A, B, C, B);
+tc.verifyEqual(ABCB(1:2, 1:2).on(), A.on());
+tc.verifyEqual(ABCB(3:4, 3).on(), B.on());
+tc.verifyEqual(ABCB(5, 4).on(), C.on());
+tc.verifyEqual(ABCB(6:7, 5).on(), B.on());
+
+zeroElements = ~logical(blkdiag(true(size(A)), true(size(B)), true(size(C)), true(size(B))));
+tc.verifyEqual(ABCB(zeroElements(:)).on(), 0*ABCB(zeroElements(:)).on());
+
+end % testBlkdiag()
+
 function testSetName(tc)
 blub = quantity.Discrete(ones(11, 2), 'grid', linspace(0, 1, 11), 'gridName', 'z');
 blub.setName('asdf');