xperm - Reorder states in state-space models

Syntax

Description

sys = xperm(sys,P) reorders the states of the state-space model sys according to the permutation P. The vector P is a permutation of 1:NX, where NX is the number of states in sys. For information about creating state-space models, see ss and dss.

Examples

Order the states in the ssF8 model in alphabetical order.

1. Load the ssF8 model by typing the following commands:

   load ltiexamples
   ssF8

   These commands return:

   a = 
                   PitchRate    Velocity         AOA  PitchAngle
      PitchRate         -0.7     -0.0458       -12.2           0
      Velocity             0      -0.014     -0.2904      -0.562
      AOA                  1     -0.0057        -1.4           0
      PitchAngle           1           0           0           0
    
   b = 
                  Elevator  Flaperon
      PitchRate      -19.1      -3.1
      Velocity     -0.0119   -0.0096
      AOA            -0.14     -0.72
      PitchAngle         0         0
    
   c = 
                     PitchRate    Velocity         AOA  PitchAngle
      FlightPath             0           0          -1           1
      Acceleration           0           0       0.733           0
    
   d = 
                    Elevator  Flaperon
      FlightPath           0         0
      Acceleration    0.0768    0.1134
    
   Continuous-time model.

2. Order the states in alphabetical order by typing the following commands:

   [y,P]=sort(ssF8.StateName);
   sys=xperm(ssF8,P)

   These commands return:

   a = 
                         AOA  PitchAngle   PitchRate    Velocity
      AOA               -1.4           0           1     -0.0057
      PitchAngle           0           0           1           0
      PitchRate        -12.2           0        -0.7     -0.0458
      Velocity       -0.2904      -0.562           0      -0.014
    
   b = 
                  Elevator  Flaperon
      AOA            -0.14     -0.72
      PitchAngle         0         0
      PitchRate      -19.1      -3.1
      Velocity     -0.0119   -0.0096
    
   c = 
                           AOA  PitchAngle   PitchRate    Velocity
      FlightPath            -1           1           0           0
      Acceleration       0.733           0           0           0
    
   d = 
                    Elevator  Flaperon
      FlightPath           0         0
      Acceleration    0.0768    0.1134
    
   Continuous-time model.

   The states in ssF8 now appear in alphabetical order.

See Also

dss | ss

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