Undefined function 'pretty' for input arguments of type 'tf'.

I want to simplify my transfer function which is hp1_tf=tf(num,den) so i used pretty(hp1_tf1) but an error would occur:

_ Undefined function 'pretty' for input arguments of type 'tf'._

Please help.

Answer 1

[Walter Roberson]

tf (transfer functions) are not sym, they just print out like that.

Using ideas from https://www.mathworks.com/matlabcentral/answers/245896-how-to-convert-a-transfer-fuction-tf-class-to-a-symbolic-equation-sym#answer_194148

syms s
sys_syms = poly2sym(cell2mat(Num),s)/poly2sym(cell2mat(Den),s);
pretty(syms_syms)