How to change line width in stepplot to then use with an updateSystem command?

Hello

Using yoru code found in https://www.mathworks.com/help/control/ug/build-app-with-interactive-plot-updates.html it seems impossible to change the line appearance (coor, width, markers, etc.)

This seems to require a peculiar plot handle that prevents using a simple plot command.

How could this be done?

Regards

S.B.

Answer 1

[Payas Bahade]

Hi Stephane,

The line appearance (color and marker) in ‘stepplot’ with interactive response-plot updates, can be changed by specifying them as input arguments. Below mentioned code illustrates how it can be done.

%Defining initial values of second-order dynamic system
zeta = .5;                           % Damping Ratio
wn = 2;                              % Natural Frequency
sys = tf(wn^2,[1,2*zeta*wn,wn^2]);
 
% Creating figure for GUI and configuring the axes for displaying step response
f = figure;
ax = axes('Parent',f,'position',[0.13 0.39  0.77 0.54]);
h = stepplot(ax,sys,'r--');% specifying marker style and color
setoptions(h,'XLim',[0,10],'YLim',[0,2]);
 
%adding slider and slider label text to the figure
b = uicontrol('Parent',f,'Style','slider','Position',[81,54,419,23],'value',zeta, 'min',0, 'max',1);
bgcolor = f.Color;
bl1 = uicontrol('Parent',f,'Style','text','Position',[50,54,23,23],'String','0','BackgroundColor',bgcolor);
bl2 = uicontrol('Parent',f,'Style','text','Position',[500,54,23,23],'String','1','BackgroundColor',bgcolor);
bl3 = uicontrol('Parent',f,'Style','text','Position',[240,25,100,23],'String','Damping Ratio','BackgroundColor',bgcolor);
 
% Setting callback that updates the step response plot as the damping ratio slider is moved.
b.Callback = @(es,ed) updateSystem(h,tf(wn^2,[1,2*(es.Value)*wn,wn^2]));

To change line width, Property inspector can be used. For this you need to navigate to required line object (Figure 1 > Axes > sys > Line) and specify the line width as required.

Output:

Hope this helps!

[Stephane Blouin]

Hello

This solution does NOT answer the question which was about "line width". So is it feasible or not? It seems that it cannot be done in a programmatic manner.

Regards

Stephane

[Payas Bahade]

Hi Stephane,

I have modified previous code to change line width programmatically. See if it solves your issue.

Code:

%Defining initial values of second-order dynamic system
zeta = .5;                           % Damping Ratio
wn = 2;                              % Natural Frequency
sys = tf(wn^2,[1,2*zeta*wn,wn^2]);
 
% Creating figure for GUI and configuring the axes for displaying step response
f = figure;
ax = axes('Parent',f,'position',[0.13 0.39  0.77 0.54]);
h = stepplot(ax,sys,'r--');% specifying marker style and color
setoptions(h,'XLim',[0,10],'YLim',[0,2]);

% To find all the graphic object handles of the figure
h1=findall(f);
% To find the line object handle from the list of graphic object handles
hline=findobj(h1,'Type','line','Tag','Curves'); 
% To set the line width
hline(1).LineWidth=4;

%adding slider and slider label text to the figure
b = uicontrol('Parent',f,'Style','slider','Position',[81,80,419,23],'value',zeta, 'min',0, 'max',1);
bgcolor = f.Color;
bl1 = uicontrol('Parent',f,'Style','text','Position',[50,80,23,23],'String','0','BackgroundColor',bgcolor);
bl2 = uicontrol('Parent',f,'Style','text','Position',[500,80,23,23],'String','1','BackgroundColor',bgcolor);
bl3 = uicontrol('Parent',f,'Style','text','Position',[240,51,100,23],'String','Damping Ratio','BackgroundColor',bgcolor);
 
% Setting callback that updates the step response plot as the damping ratio slider is moved.
b.Callback = @(es,ed) updateSystem(h,tf(wn^2,[1,2*(es.Value)*wn,wn^2]));

Output:

HTH!