By the way, it doesn't support the FOH approximation method!
Maybe TUSTIN can work the same.
Thank you anyway.
Do you want to make us a FOH method?
FYI - the control package page can be found here:
you can compare any function there with it's matlab equivalent by searching on the mathworks site. doing so for c2d reveals that under Methods:
'zoh' — Zero-order hold (default). Assumes the control inputs are piecewise constant over the sample time Ts.
'foh' — Triangle approximation (modified first-order hold). Assumes the control inputs are piecewise linear over the sample time Ts.
'impulse' — Impulse invariant discretization
'tustin' — Bilinear (Tustin) method
'matched' — Zero-pole matching method
while Octave supports:
’impulse’ Impulse Invarient transformation.
’zoh’ Zero-order hold or matrix exponential.
’tustin’, ’bilin’ Bilinear transformation or Tustin approximation.
’prewarp’ Bilinear transformation with pre-warping at frequency w0.
’matched’ Matched pole/zero method.
similarly, the Control package wiki contains a listing of implementation status, so you can see things that would be useful to get help on: