[Open] [PATCH 0/1]Add #adjugate method to matrix class

Ruby Development
1

Issue #10056 has been reported by gogo tanaka.

Feature #10056: [PATCH 0/1]Add #adjugate method to matrix class

  • Author: gogo tanaka
  • Status: Open
  • Priority: Normal
  • Assignee:
  • Category:
  • Target version:

Add Matrix#adjugate to make a matrix adjugate.

Adjugate is really important operator to handle matrix (especially
Exploring Data with ruby)

# Property

* Any n-th matrix  `m`(object of Matrix class) Satisfy the following 
conditions

Matrix.identity(n) == (m.adjugate * m) / m.det

# Differential vector or matrix
Let A = (a(i, j)) is n-th matrix, A(i, j) is adjugate matrix excluding 
the j and column i row A.

def. ∂det(A)/∂a(i,j) = (-1) ** (i + j) * det(A(i, j))

Some people regards adjugate matrix as Hermitian adjoint.

I regard adjuate matrix as transpose of the cofactor matrix by
referencing Adjugate matrix - Wikipedia.