test source folder pwd

Author: taguptamw

plugins/+matlab/+unittest/+internal/+services/+plugins/QuadraticPolynomial.m

@@ -0,0 +1,41 @@
+classdef QuadraticPolynomial
+    properties
+        A,B,C   % Coefficients of a*x^2 + b*x + c
+    end
+
+    methods
+        function obj = QuadraticPolynomial(a,b,c)
+            if ~isa(a,"numeric") || ~isa(b,"numeric") || ~isa(c,"numeric")
+                error("QuadraticPolynomial:InputMustBeNumeric", ...
+                    "Coefficients must be numeric.")
+            else
+                obj.A = a; obj.B = b; obj.C = c;
+            end
+        end
+
+        function r = solve(obj)
+            % Return solutions to a*x^2 + b*x + c = 0
+            delta = calculateDelta(obj);
+            r(1) = (-obj.B - sqrt(delta)) / (2*obj.A);
+            r(2) = (-obj.B + sqrt(delta)) / (2*obj.A);
+        end
+
+        function plot(obj,ax)
+            % Plot a*x^2 + b*x + c around its axis of symmetry
+            delta = calculateDelta(obj);
+            x0 = -obj.B/(2*obj.A);
+            x1 = abs(sqrt(delta))/obj.A;
+            x = x0 + linspace(-x1,x1);
+            y = obj.A*x.^2 + obj.B*x + obj.C;
+            plot(ax,x,y)
+            xlabel("x")
+            ylabel(sprintf("%.2fx^2%+.2fx%+.2f",obj.A,obj.B,obj.C))
+        end
+    end
+
+    methods (Access=private)
+        function delta = calculateDelta(obj)
+            delta = obj.B^2 - 4*obj.A*obj.C;
+        end
+    end
+end