Just play around a little bit with how you call specific indices out of a structure, it will become easy once you get the hang of it. For example:
plot(data.Electric_Field.Ex.data(:,1),data.Electric_Field.Ex.data(:,2))
This will plot the first column of the data matrix in the Ex structure in the Electric Field structure in the data structure against the 2nd column of the same structure. Give it a try! :)
