transfer function and loops

Hello, I am trying to create a matlab file that will take a transfer function with a symbolic variable i and print the poles and display the pzplot for each value of i if i put it into a loop. so for instance, here is the code I tried.

for i = 1:5 num = [1]; dem = [1 4 (i-4) (8*i)]; pzplo(f) end;

I want it to plot all of the poles from i=1 to i=5 but it will only display the last one. I tried putting the function into an array and referring to the indices to plot out the poles, but I can't use an array with a transfer function i guess because it says it cant convert from double to tf. I dont know how to make a non-double array. any help would be greatly appreciated, thanks

Answer 1

[Walter Roberson]

Hints:

• read the documentation for "hold"
• read the documentation for cell arrays

[me]

I see thanks. I can use the hold function.