You can use the built-in method all() of matlab to check, if all array elements are nonzero or not. As every element of your cell matrix is a matrix of say n rows and 2 columns, you could use all() method before plotting the graph for each cell.For eg.
>> B = [0 0; 0 0; 0 0; 0 0]
B =
0 0
0 0
0 0
0 0
>> all(B(:)==0)
ans =
logical
1
>> A = [1 0; 0 0; 1 2; 0 0]
A =
1 0
0 0
1 2
0 0
>> all(A(:)==0)
ans =
logical
0
Plot the graph only when you get 0 as the output.
