在官网给appdesigner的一个例子中中出现simOut.y.signals(2).values，其中y是什么意思？

这是官网例子（

try
app.toggleUIC('off', 'Simulating ...');

            % create the simulation input
            simInp = Simulink.SimulationInput('MassSpringDamperModel');%给信号输入仿真文件加一个句柄。

            % set the parameters for this run
            simInp = simInp.setVariable('k',app.StiffnessSpinner.Value);
            simInp = simInp.setVariable('m',app.MassSpinner.Value);
            simInp = simInp.setVariable('b',app.DampingSpinner.Value);
            simInp = simInp.setVariable('x0',app.InitialPositionEditField.Value);%输入变量，也就是改变其中的变量。
            
            % set the model parameters for this run设置运行时间给这个文件。
            stopTimeStr = num2str(app.StopTimeSpinner.Value);
            simInp = simInp.setModelParameter('StopTime', stopTimeStr);

            % set the external input for this run，
            simInp.ExternalInput = app.externalInput();

            % configure simInp for deployment,
            simInp = simulink.compiler.configureForDeployment(simInp);
            % DEBUG TIP: Comment out the line above for faster debug
            % iterations when runnng this app in the MATLAB desktop.
            
            % run
            simOut = sim(simInp);
            
            % extract and plot the results,
 **           t = simOut.y.time;
            yp = simOut.y.signals(1).values;
            yv = simOut.y.signals(2).values;**
            plot(app.PositionUIAxes, t, yp);
            plot(app.VelocityUIAxes, t, yv);
        catch ME
            errordlg(ME.message);    
        end
        app.toggleUIC('on', 'Simulate');