How can I change the label after using my sim function

A = [0.9607, 0.0196, 0.1776; -0.0098, 0.9999, -0.0009; 0, 0, 0.8187];
B = [0.0185, 0.1974; -0.0001, 0.1390; 0.1813, 0];
C = [1, 0, 0; 0, 1, 0; 0, 0, 1];
Ts = 0.2;
sys = ss(A, B, C, 0, Ts);
% States  : HP = Head Perturbation; SP = Stock-level Perturbation; AP = Air
% Valve Perturbation
% Controls: AV = Air Valve; SV = Stock Valve
model = setmpcsignals(sys,'MV',[1,2],'MO',[1,2,3]);
% controller object, sampling period, prediction hor., control hor.
mpcobj = mpc(model, Ts, 10, 10);

-->"Weights.ManipulatedVariables" is empty. Assuming default 0.00000.
-->"Weights.ManipulatedVariablesRate" is empty. Assuming default 0.10000.
-->"Weights.OutputVariables" is empty. Assuming default 1.00000.
   for output(s) y1 y2 and zero weight for output(s) y3 

% Input constraints
mpcobj.MV(1,1).Min = -5;
mpcobj.MV(1,1).Max =  5;
mpcobj.MV(1,2).Min = -10;
mpcobj.MV(1,2).Max =  10;
% Output Constraints
mpcobj.OV(1,1).Min = 0;
mpcobj.OV(1,1).Max = 50;
mpcobj.OV(1,2).Min = 0;
mpcobj.OV(1,2).Max = 25;
Tstop = 30;                               % simulation time
Tf = round(Tstop/Ts);                     % number of simulation steps
r = 10*ones(Tf,3);                        % reference signal
sim(mpcobj,Tf,r)

-->Assuming output disturbance added to measured output #1 is integrated white noise.
-->Assuming output disturbance added to measured output #2 is integrated white noise.
-->Assuming output disturbance added to measured output #3 is integrated white noise.
-->"Model.Noise" is empty. Assuming white noise on each measured output.

This is my matlab code for MPC. After I use the sim function there are two graphs and I would like to change the label of them. If I use title, I can only change one of them. is there a way that I can directly change the titles without using several plot functions and regenerate my graphs?

Answer 1

[Walter Roberson]

A = [0.9607, 0.0196, 0.1776; -0.0098, 0.9999, -0.0009; 0, 0, 0.8187];
B = [0.0185, 0.1974; -0.0001, 0.1390; 0.1813, 0];
C = [1, 0, 0; 0, 1, 0; 0, 0, 1];
Ts = 0.2;
sys = ss(A, B, C, 0, Ts);
% States  : HP = Head Perturbation; SP = Stock-level Perturbation; AP = Air
% Valve Perturbation
% Controls: AV = Air Valve; SV = Stock Valve
model = setmpcsignals(sys,'MV',[1,2],'MO',[1,2,3]);
% controller object, sampling period, prediction hor., control hor.
mpcobj = mpc(model, Ts, 10, 10);

-->"Weights.ManipulatedVariables" is empty. Assuming default 0.00000.
-->"Weights.ManipulatedVariablesRate" is empty. Assuming default 0.10000.
-->"Weights.OutputVariables" is empty. Assuming default 1.00000.
   for output(s) y1 y2 and zero weight for output(s) y3 

% Input constraints
mpcobj.MV(1,1).Min = -5;
mpcobj.MV(1,1).Max =  5;
mpcobj.MV(1,2).Min = -10;
mpcobj.MV(1,2).Max =  10;
% Output Constraints
mpcobj.OV(1,1).Min = 0;
mpcobj.OV(1,1).Max = 50;
mpcobj.OV(1,2).Min = 0;
mpcobj.OV(1,2).Max = 25;
Tstop = 30;                               % simulation time
Tf = round(Tstop/Ts);                     % number of simulation steps
r = 10*ones(Tf,3);                        % reference signal
sim(mpcobj,Tf,r)

-->Assuming output disturbance added to measured output #1 is integrated white noise.
-->Assuming output disturbance added to measured output #2 is integrated white noise.
-->Assuming output disturbance added to measured output #3 is integrated white noise.
-->"Model.Noise" is empty. Assuming white noise on each measured output.

figs = get(0,'Children');

T = findall(figs, 'string', 'Plant Outputs')

T = 
  Text (Plant Outputs) with properties:

                 String: 'Plant Outputs'
               FontSize: 11
             FontWeight: 'bold'
               FontName: 'Helvetica'
                  Color: [0 0 0]
    HorizontalAlignment: 'center'
               Position: [277.5003 356.7500 -0.8087]
                  Units: 'pixels'

  Use GET to show all properties

Tax = T.Parent

Tax = 
  Axes (Plant Outputs) with properties:

             XLim: [0 1]
             YLim: [0 1]
           XScale: 'linear'
           YScale: 'linear'
    GridLineStyle: '-'
         Position: [0.0665 0.0830 0.9575 0.8154]
            Units: 'normalized'

  Use GET to show all properties

Tax.Tag

ans =

  0×0 empty char array

Tax.Title

ans = 
  Text (Plant Outputs) with properties:

                 String: 'Plant Outputs'
               FontSize: 11
             FontWeight: 'bold'
               FontName: 'Helvetica'
                  Color: [0 0 0]
    HorizontalAlignment: 'center'
               Position: [277.5003 356.7500 -0.8087]
                  Units: 'pixels'

  Use GET to show all properties

Tax.HandleVisibility

ans = 'off'

In summary, the name Plant Outputs is a Title within a hidden axes. You can findall() it and then change its String property.

[Jialu Yao]

Thanks! I solved it