An easy way to execute complicated functions in Simulink is to use the Embedded MATLAB Function block. When you insert one of these blocks it creates a MATLAB file that is contained within the Simulink model block. The issue with this block is that only a subset of the full MATLAB language is available within an Embedded block. The simple solution to this problem is the function *eml.extrinsic* which sets certain functions to execute externally.

*Example:*

`eml.extrinsic('myfunction');`

[outputa outputb] = myfunction(inputa, inputb);

The function names within the *extrinsic* call will be set to run within MATLAB instead of Simulink. Now functions like *tf* and *ss* can be used!

Another Embedded MATLAB tip is to use ‘*1i’ to represent complex numbers. (This is mentioned in the MATLAB documentation but looks like ‘li’.)

*References:
http://www.mathworks.com/help/toolbox/simulink/ug/f6-106261.html*