ml_order
Order computation for model reduction methods.
Contents
Syntax
nr = ml_order(hsv, tselect) nr = ml_order(hsv, tselect, opts)
Description
This function computes the size of the resulting reduced-order model based on a given vector of characteristic values and appropriate error formulas.
Input
- hsv - a vector, containing the characteristic values of the system
- nu - an integer, number of states corresponding to anti-stable eigenvalues of the system's matrix pencil
- ni - an integer, number of states corresponding to infinite eigenvalues of the system's matrix pencil
- tselect - an integer, used to determine the computation method for the {!} order of the reduced-order model 0 - order is directly given by user 1 - computed by a relative tolerance for the hsv 2 - computed by a relative tolerance on the sum of hsv 3 - computed by absolute error bound of BT 4 - computed by relative error bound of BST 5 - computed by absolute error bound of LQGBT 6 - computed by absolute error bound of HinfBT
- opts - structure, containing the following optional entries:
Parameter | Meaning |
Gamma | positive scalar, scaling term from the H-infinity balanced truncation default: Inf |
Order {!} | positive integer, order of the resulting reduced-order model chosen by the user if tselect == 0 default: min(10,length(hsv)) + nu + ni |
Tolerance {!} | nonnegative scalar, tolerance used in the different error formulas default: 1.0e-02 |
Note: Parameters marked with {!} may also be a cell array containing multiple arguments. In this case an cell array of the same size is returned with one entry computed for each input argument and the marked fields of the info struct are cells as well. When multiple arguments are given as cells, they are expected to have the same length.
Output
- nrs - size of the reduced-order model
See Also