Hi 向华,
由于我的母语不是中文，我将用英语回答这个问题。
"tf" function is part of the Control System Toolbox product, which is an optional product that must be licensed and installed. Follow the given steps to troubleshoot the issue you are facing:
- Run the following command to find out which "tf" function is being called:
which -all tf
- "MATLAB\R2022a\toolbox\control\ctrlmodels\@tf\tf.m" should be present among the results.
- Check if Control System Toolbox is licensed and installed by using the following command:
ver control
- Click "Adds-Ons" in the MATLAB application and download "Control Systems Toolbox", to install the Control System Toolbox if not already installed.
Hope this resolves your issue!
