serial communication to matlab for graph ploting

I am new to serial communication and I am trying to do a project where I can interface matlab with my pic18f14k50. now i am able to getting the data from the PIC. the problem is how can i plot the graph in matlab by using the PIC data.
i dunno why my data getting from PIC is show as char in matlab workspace. who can help change it data to array in workspace which able to plot graph.