Z transform - choice of z?

Started by September 23, 2005
>From scratching around on the internet and reading Hamming's Digital
Filters book it appears that the z transform is used pretty much only with z = exp(iw), which means it works like a discrete Fourier transform. I was wondering whether the z transform is ever used with z = exp(iw+y). This seems to be remarkably useful - I wonder if it is impractical to compute for a given signal, therefore not used in practice.
spasmous@yahoo.com wrote:

>>From scratching around on the internet and reading Hamming's Digital > Filters book it appears that the z transform is used pretty much only > with z = exp(iw), which means it works like a discrete Fourier > transform. > > I was wondering whether the z transform is ever used with z = > exp(iw+y). This seems to be remarkably useful - I wonder if it is > impractical to compute for a given signal, therefore not used in > practice. >
In control systems the z transform is used as z = exp(sT), with T = sampling rate & s being the frequency variable in the Laplace transform. It has some conversion issues that the mathematicians quibble about, but it works just fine so there must be some way of dancing around them... -- Tim Wescott Wescott Design Services http://www.wescottdesign.com
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