How to calculate the transfer function for a 16 input system?

Hi, I have a system output dependant of 16 inputs, I am doing tests and I have the outputs values for some sets of inputs, how could I calculate the transfer function?, thanks

Answer 1

[Khaled Hamed]

It depends on what type of Transfer Function you want to use. For example, if you want to use an ARX model (I am using random inputs and output here, which you can replace with your own data) :

x=randn(100,16);
y=x*randi(10,16,1);
a=arx(iddata(y,x,1),[1 ones(1,16) zeros(1,16)]);

You will need the System Identification toolbox. There are several models which include a transfer function component, such as BJ, ARX, and ARMAX.

Or you can use:

a=tfest(iddata(y,x,1),0,0)

Of course you may want to change the number of poles, zeros, or the delays for each input.

Answer 2

[Rajiv Singh]

Try also TFEST. Although you might want to reduce the number of inputs by PCA or PLS analysis.

[Khaled Hamed]

Excellent advice, especially if the inputs are correlated.