minv, vinv (Mu Analysis and Synthesis Toolbox)

Calculate the inverse of CONSTANT, SYSTEM, and VARYING matrices. (The matrices must be square.)

Syntax

out = minv(mat) 
out = vinv(mat)

Description

minv calculates the inverse of the input matrix. For VARYING matrices, minv returns a VARYING matrix with the inverse of each independent variable matrix. For SYSTEM matrices, the inverse is defined as

vinv is the same command as minv, but works only on CONSTANT and VARYING matrices.

Examples

Determine the inverse of a SYSTEM matrix and a VARYING matrix.

sys = pck(-2,3,1,.1); 
omega = [1 10]; 
sysg = frsp(sys,omega); 
sysi = minv(sys); 
seesys(sysi)

-3.2e+01  |   -3.0e+01
----------|-----------
1.0e+01   |    1.0e+01

sysig = frsp(sysi,omega); 
see(sbs(sysg,sysig,minv(sysig)))
1 row   3 columns
iv =
1.3000 - 0.6000i   0.6341 + 0.2927i   1.3000 - 0.6000i
iv = 10
0.1577 - 0.2885i   1.4591 + 2.6690i   0.1577 - 0.2885i

Algorithm

minv and vinv call the MATLAB inv command.