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
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

Output

nr - size of the reduced-order model

See Also

ml_ct_dss_bfsr | ml_ct_ss_bfsr | ml_ct_dss_sr | ml_ct_ss_sr