How do I tell Matlab to Label the point where my subplots are equal?

I'm trying to write a For loop for when KE (Subplot #1) is equal to PE (Subplot #2) and label it as an asterisk. Below is part of my main script and attached is a picture of the graph.

 for n = 1:7
      figure(2);
      KE{n} = 0.5*m*(U{n}.^2 + V{n}.^2 + W{n}.^2 );
      PE{n} = m*g*Z{n} ;
      hold on
      subplot(2,1,1);
      plot(T{n},KE{n},color(n));
   subplot(2,1,2);
      plot(T{n},PE{n},color(n))

My attempt. I tried setting a For Loop for each line, such that when KE = PE, Matlab wouldd label the point as an asterick for both plots.

for n = 1:7
    if KE{n}==PE{n}
    subplot(2,1,1)
    plot(KE{n}==PE{n},['*' color(n)]);
  hold on
    subplot(2,1,2)
    plot(PE{n}==KE{n},['*' color(n)]);
end

Answer 1

[KL]

Why are you using a cell array? It looks like you're better off with a numeric array and then you also wouldn't need a loop in that case. To calculate KE and PE, it's simply,

 %dummy data
 U = rand(10,7);
 V = rand(10,7);
 W = rand(10,7);
 Z = rand(10,7);

 %calculate KE and PE,
 KE = 0.5*m*(U.^2+V.^2+W.^2);
 PE = m*g*Z;

 %now find the common elements,
 C = bsxfun(@eq,KE,PE);

 %now plot
 figure(1)
 subplot(2,1,1)
 plot(KE)
 hold on
 plot(KE(C),'-*')
 hold off

 %and similar for PE

Hope this is what you were looking for.