# How to define sensitivity studies / optimization output variables?

MANATEE electromagnetic and vibroacoustic models can be called in sensitivity studies or optimization loops. In both cases one must define the output (also called response) variables.

A first way to define these output variables is to use the default Output variables of MANATEE software. Similarly to input variables, the names and description of the output variables can be found in MANATEE_Output_variables.xlsx Excel file of the /Doc folder. As an example, to look at the torque and the maximum sound power level at variable speed one should specify :

`Input.Simu.names_resp={'LwrA_max';'Cout'};`

Alternatively, one can define its own output variables by defining post processing script. This process is detailed in how to use user defined input/output variables article.

Finally, one can also use pre-defined scripts in MANATEE. The list of these special scripts is the following:

• get_ASPL_speed
• get_ASPL_freq

To minimize the A-weighted sound pressure level at a specific speed of 1500 rpm one can simply include as an output variable ’get_ASPL_speed(1500)’. Similarly to observe the magnitude of a specific noise harmonic at nominal speed at 12 times the electrical frequency, one can use ’get_ASPL_freq(12)’ at an output variable.