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Scilab Help >> Polynomials > invr

invr

inverts a matrix of polynomials or of rationals

Syntax

F = invr(H)

Arguments

H

polynomial or rational matrix

F

polynomial or rational matrix

Description

invr computes H-1 using Leverrier's algorithm (see function's code).

Examples

s = %s;
H = [s, s*s+2 ; 1-s, 1+s], iH = invr(H), H * iH

[Num,den] = coffg(H); Num/den
H = [1/s, (s+1) ; 1/(s+2), (s+3)/s]; invr(H)
--> H = [s, s*s+2 ; 1-s, 1+s], iH = invr(H), H * iH
 H  =
  s     2 +s²
  1 -s  1 +s

 iH  =
      1 +s       -2 -s²
   ----------  ----------
   -2 +3s +s³  -2 +3s +s³

     -1 +s         s
   ----------  ----------
   -2 +3s +s³  -2 +3s +s³

 ans  =
   1  0
   -  -
   1  1

   0  1
   -  -
   1  1

--> [Num,den] = coffg(H); Num/den
 ans  =
      1 +s       -2 -s²
   ----------  ----------
   -2 +3s +s³  -2 +3s +s³

     -1 +s         s
   ----------  ----------
   -2 +3s +s³  -2 +3s +s³

See also

  • inv — matrix inverse
  • glever — inverse of matrix pencil
  • coffg — Co-factors of a matrix of polynomials or rationals
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Last updated:
Mon Jan 03 14:23:25 CET 2022