Discretization MethodsΒΆ
In harold, a discrete time model can keep the discretization method in mind such that when the occasion arises to convert back to a continuous model the proper method is chosen. For example suppose we discretized a state model via Zero-order-hold:
# Take a polynomial and make the corresponding companion matrix
G = State(haroldcompanion([1,2,3,4]),eyecolumn(3,2),eyecolumn(3,0).T)
F = discretize(G,0.01,method='zoh') # default method is 'tustin'
Now if we actually check the properties of F
we can see what it
actually keeps:
F.DiscretizedWith # returns 'zoh'
F.SamplingPeriod # returns 0.01
F.SamplingSet # returns 'Z'
Currently, the known discretization methods are given as
Method | Aliases |
bilinear |
|
forward difference |
|
backward difference |
|
lft |
|
zoh |
Hence, if a model with DiscretizedWith
property set to
something else then None
, then the continuous time conversion
actually takes it into account, and uses that method on the way
back.
Todo
Explain these methods and of course undiscretize()
stuff more!!