Hello,
LabVIEW MathScript does not require any additional third-party software to work. Certain functions that you mention (tf, pzmap) are available in MathScript if you purchase the LabVIEW Control Design and Simulation Module. MathScript does not currently have support for symbolic mathematics (e.g. sym). However, if you meant the "sim" function, the LabVIEW Control Design and Simulation Module can convert your .MDL file to a VI with a LabVIEW simulation node. You can then connect the rest of your script to the simulation node with a MathScript node.
Grant M.
Staff Software Engineer | LabVIEW Math & Signal Processing | National Instruments