Why am I getting the error "Invalid or Deleted Object"

This is my code

%constants A and B calculations
y1 = Mean(1);
x1 = Mean_step(1);
initial = y1*x1;
y2 = Mean(2);
x2 = Mean_step(2);
constant_B = (x2*y2-initial)/(y1-y2);
constant_A=(initial)+((y1)*constant_B);

%model calculation
Model = constant_A./(Mean_step + constant_B);
hp = plot(Mean_step, Model, 'r-', 'Linewidth', 1.5);

%%%dynamic text

txt1 = ['V_{preamp} = ' num2str(constant_A) ' / (Tool-Substrate Gap + (' num2str(constant_B) '))'];
ht = text(400, 650, txt1, 'FontSize', 9);
txt2 = ['Current V_{preamp} value = ' num2str(Mean(k)) '| Current Z-piezo distance = (' num2str(Mean_step(k)) '))'];
ht2 = text(400, 600, txt2, 'FontSize', 9);
txt3 =['Current Z-piezo distance = ' num2str(Mean_step(k)) ''];
ht3 = text(400, 550, txt3, 'FontSize', 9);
txt4 = ['Percentage Change = ' num2str(percent_change)];
ht4 = text(400 , 500, txt4, 'FontSize', 9);


%animated line handle, the line after the trailing dot
hh=animatedline('Marker','o','MarkerSize', 3,'MarkerFaceColor',[0.2 0.2 0.2]);
%trailing dot handle
h = plot(nan, nan, 'yo', 'MarkerSize', 5, 'MarkerFaceColor', 'g','MarkerEdgeColor','g');   %yellow, filled, large



for k = 2:length(Mean)
    y2=Mean(k);
    x2=Mean_step(k);
      
    constant_B=(x2*y2-initial)/(y1-y2);
     
    constant_A=(initial)+((y1)*constant_B);
     
    Model = constant_A./(Mean_step + constant_B);
    
    hp.YData = Model;
  
    
    txt1 = ['V_{preamp} = ' num2str(constant_A) ' / (Tool-Substrate Gap + (' num2str(constant_B) '))'];
    ht.String = txt1;
    
    addpoints(hh, Mean_step(k), Mean(k))
    
    txt2 = ['Current V_{preamp} value = ' num2str(Mean(k)) ' V'];
    ht2.String = txt2;
    txt3 =['Current Z-piezo distance = ' num2str(Mean_step(k)) ' \mum'];
    ht3.String = txt3;
    txt4 = ['Percentage Change = ' num2str(percent_change)];
    ht4.String = txt4;
    
    set(h, 'XData', Mean_step(k), 'YData', Mean(k));
    
    
    drawnow()
end

[Hans123]

I think the handle is overwritten, I updated the question and pasted my original code

Answer 1

[Adam Danz]

Problem

First you produce a plot and assign the handle to hp

hp = plot(Mean_step, Model, 'r-', 'Linewidth', 1.5);

Then you destroy that plot and overwrite it with this line.

h = plot(nan, nan, 'yo', 'MarkerSize', 5, 'MarkerFaceColor', 'g','MarkerEdgeColor','g');   %yellow, filled, large

When you get to this line of code (below) hp is no longer a valid object since it was deleted.

 hp.YData = Model;

Solution

Option 1: hold on.

 hp = plot(Mean_step, Model, 'r-', 'Linewidth', 1.5);
 hold on  %now the 2nd line will be added to the plot

Option 2: new figure

 figure()
 h = plot(nan, nan, 'yo', 'MarkerSize', 5, 'MarkerFaceColor', 'g','MarkerEdgeColor','g');   %yellow, filled, large
% now the two lines will be on two different figures. 

[Hans123]

Ah.... that solves everything, thank you.

[Adam Danz]

Glad I could help. I knew to look for one of these:

• delete(obj)
• clear(obj)
• more than 1 plot without a "hold on" <--- this was the culprit
• Accessing an undefined variable <---- could have been this (we don't have values for several of your variables).

[Hans123]

thanks for showing me your thought process, really appreciate it!

cheers