Block Matrices from Rows and Columns #
This file provides the basic definitions of matrices composed from columns and rows.
The concatenation of two matrices with the same row indices can be expressed as
A = fromColumns A₁ A₂
the concatenation of two matrices with the same column indices
can be expressed as B = fromRows B₁ B₂
.
We then provide a few lemmas that deal with the products of these with each other and with block matrices
Tags #
column matrices, row matrices, column row block matrices
A column partitioned matrix when transposed gives a row partitioned matrix with columns of the initial matrix transposed to become rows.
A row partitioned matrix when transposed gives a column partitioned matrix with rows of the initial matrix transposed to become columns.
A row partitioned matrix multiplied by a column partitioned matrix gives a 2 by 2 block matrix.
A column partitioned matrix multiplied by a row partitioned matrix gives the sum of the "outer" products of the block matrices.
A column partitioned matrix multipiled by a block matrix results in a column partitioned matrix.
A block matrix multiplied by a row partitioned matrix gives a row partitioned matrix.
Multiplication of a matrix by its inverse is commutative.
This is the column and row partitioned matrix form of Matrix.mul_eq_one_comm
.
The condition e : n ≃ n₁ ⊕ n₂
states that fromColumns A₁ A₂
and fromRows B₁ B₂
are "square".
The lemma fromColumns_mul_fromRows_eq_one_comm
specialized to the case where the index sets n₁
and n₂, are the result of subtyping by a predicate and its complement.
A column partitioned matrix in a Star ring when conjugate transposed gives a row partitioned matrix with the columns of the initial matrix conjugate transposed to become rows.
A row partitioned matrix in a Star ring when conjugate transposed gives a column partitioned matrix with the rows of the initial matrix conjugate transposed to become columns.