quantity: added unitary minus and plus (uminus and uplus): -quant = (-1)*quant

+quantity/Discrete.m

@@ -1487,6 +1487,18 @@ classdef  (InferiorClasses = {?quantity.Symbolic, ?quantity.Operator}) Discrete
 			[C.name] = deal([A(1).name, '-', B(1).name]);
 		end
 		
+		
+		function C = uplus(A)
+			% unitary plus: C = +A
+			C = copy(A);
+		end
+		
+		function C = uminus(A)
+			% unitary plus: C = -A
+			C = (-1) * A;
+			[C.name] = deal(['-', A(1).name]);
+		end
+		
 		function [P, supremum] = relativeErrorSupremum(A, B)
 			
 			assert(numel(A) == numel(B), 'Not implemented')

+unittests/+quantity/testDiscrete.m

@@ -4,6 +4,23 @@ function [tests] = testDiscrete()
 tests = functiontests(localfunctions);
 end
 
+function testUnitaryPluasAndMinus(testCase)
+syms z zeta
+qSymbolic = quantity.Symbolic(...
+	[1+z*zeta, -zeta; -z, z^2], 'grid', {linspace(0, 1, 21), linspace(0, 1, 41)},...
+	'variable', {z, zeta}, 'name', 'q');
+qDiscrete = quantity.Discrete(qSymbolic);
+qDoubleArray = qSymbolic.on();
+
+testCase.verifyEqual(on(-qSymbolic), -qDoubleArray);
+testCase.verifyEqual(on(-qDiscrete), -qDoubleArray);
+testCase.verifyEqual(on(+qSymbolic), +qDoubleArray);
+testCase.verifyEqual(on(+qDiscrete), +qDoubleArray);
+testCase.verifyEqual(on(+qDiscrete), on(+qSymbolic));
+testCase.verifyEqual(on(-qDiscrete), on(-qSymbolic));
+
+end
+
 function testConcatenate(testCase)
 
 t = linspace(0, pi)';