Talk:Control Systems/Z Transform Mappings

==Bilinear Transform

The bilinear transform is effectively just the Z-transform with a multiplier reflecting frequency. see for an example.--Billymac00 18:10, 28 December 2006 (UTC)

Approximation
As I understand it, the 2*(z-1)/(z+1) is a crude linear approximation to ln(z). It is decent for z 0.7 to 0.99 but I caution for range 0+ to 0.70. That range is better served by a cubic fit.--Billymac00 (discuss • contribs) 23:56, 8 January 2015 (UTC)