the function ss appears to me included in a number of toolboxes >> which -all ss
Kshitij Singh answered .
2025-11-20
>> which -all ss /Applications/MATLAB_R2016b.app/toolbox/control/ctrlmodels/@ss/ss.m % ss constructor /Applications/MATLAB_R2016b.app/toolbox/signal/signal/@dfilt/ss.m % dfilt method /Applications/MATLAB_R2016b.app/toolbox/control/ctrlmodels/@DynamicSystem/ss.m % DynamicSystem method /Applications/MATLAB_R2016b.app/toolbox/shared/controllib/engine/@StaticModel/ss.m % StaticModel method /Applications/MATLAB_R2016b.app/toolbox/mpc/mpc/@mpc/ss.m % mpc method
You are missing the first of those, the Control System Toolbox class constructor of ss . It appears to me that you might not have that toolbox installed.