Hi,
I get extrange values in DIAdem when I apply a digital filter. I give you an example. If I use an IIR 2 order Digital filter, then the filter's formula should be y(n) = b1*x(n) + b(2)*x(n-1) + b(3)*x(n-2) - a2*y(n-1) - a3*y(n-2). where y is the filtered signal and x is the data signal.
If for example I filter a random signal, I have x and y arrays, and I can forward by a system of equations get coefficients b1,b2,b3,a2,a3.
But here comes my questions, depends on wich n value I use in the above formula, I get different values from b1,b2,b3,a2,a3, so it is like if the formula is wrong.
Anyone knows what exactly this IIR digital filter function does? I have use ChnFiltCalc function but like I said, I am not pretty sure about which formula this function uses in order to calculate the y(n) array.
Best regards and I hope someone can help me to understand that!
Ignacio
