Mathematica: how to make Z transformation of data from CSV File

Question

I have a discrete Signal in my CSV File and I want to transform it in Z. I import the data with

 Data=Import["T:/data.csv","CSV"]

and I try to transform it

ZTranform[Data[n],n,z]

but I get this Error:

$RecursionLimit::reclim : Recursion depth of 256 exceeded >>

What is the meaning of this?

Answer 1

I think you are confused on ZTransform. This expects to take an expression as a function of n, for example n^2 2^(-n). If you have just numbers, then you can't do this. You need to apply the formula itself. Assuming one-sided ZTransform, then simply write

Clear[z, n]
data = RandomReal[{0, 1}, 10];
Sum[data[[n + 1]] z^(-n), {n, 0, Length[data] - 1}]

This is simply the definition. http://mathworld.wolfram.com/Z-Transform.html

Replace data above with your own data in the CVS file. Again, I used a one-sided ZTransform in this example, which is the most common one.