Matrices as a normed space #
In this file we provide the following non-instances for norms on matrices:
The elementwise norm:
The Frobenius norm:
The $L^\infty$ operator norm:
These are not declared as instances because there are several natural choices for defining the norm of a matrix.
The norm induced by the identification of Matrix m n 𝕜
with
EuclideanSpace n 𝕜 →L[𝕜] EuclideanSpace m 𝕜
(i.e., the ℓ² operator norm) can be found in
Analysis.CstarAlgebra.Matrix
. It is separated to avoid extraneous imports in this file.
The elementwise supremum norm #
Seminormed group instance (using sup norm of sup norm) for matrices over a seminormed group. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.seminormedAddCommGroup = Pi.seminormedAddCommGroup
Instances For
The norm of a matrix is the sup of the sup of the nnnorm of the entries
Equations
- ⋯ = ⋯
Note this is safe as an instance as it carries no data.
Equations
- ⋯ = ⋯
Normed group instance (using sup norm of sup norm) for matrices over a normed group. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.normedAddCommGroup = Pi.normedAddCommGroup
Instances For
This applies to the sup norm of sup norm.
Normed space instance (using sup norm of sup norm) for matrices over a normed space. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.normedSpace = Pi.normedSpace
Instances For
The $L_\infty$ operator norm #
This section defines the matrix norm $\|A\|_\infty = \operatorname{sup}_i (\sum_j \|A_{ij}\|)$.
Note that this is equivalent to the operator norm, considering $A$ as a linear map between two $L^\infty$ spaces.
Seminormed group instance (using sup norm of L1 norm) for matrices over a seminormed group. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.linftyOpSeminormedAddCommGroup = inferInstance
Instances For
Normed group instance (using sup norm of L1 norm) for matrices over a normed ring. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.linftyOpNormedAddCommGroup = inferInstance
Instances For
This applies to the sup norm of L1 norm.
Normed space instance (using sup norm of L1 norm) for matrices over a normed space. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.linftyOpNormedSpace = inferInstance
Instances For
Alias of Matrix.linfty_opNorm_def
.
Alias of Matrix.linfty_opNNNorm_def
.
Alias of Matrix.linfty_opNNNorm_col
.
Alias of Matrix.linfty_opNorm_col
.
Alias of Matrix.linfty_opNNNorm_row
.
Alias of Matrix.linfty_opNorm_row
.
Alias of Matrix.linfty_opNNNorm_diagonal
.
Alias of Matrix.linfty_opNorm_diagonal
.
Alias of Matrix.linfty_opNNNorm_mul
.
Seminormed non-unital ring instance (using sup norm of L1 norm) for matrices over a semi normed non-unital ring. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.linftyOpNonUnitalSemiNormedRing = let __src := Matrix.linftyOpSeminormedAddCommGroup; let __src_1 := Matrix.instNonUnitalRing; NonUnitalSeminormedRing.mk ⋯ ⋯
Instances For
The L₁-L∞
norm preserves one on non-empty matrices. Note this is safe as an instance, as it
carries no data.
Equations
- ⋯ = ⋯
Seminormed ring instance (using sup norm of L1 norm) for matrices over a semi normed ring. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.linftyOpSemiNormedRing = let __src := Matrix.linftyOpNonUnitalSemiNormedRing; let __src_1 := Matrix.instRing; SeminormedRing.mk ⋯ ⋯
Instances For
Normed non-unital ring instance (using sup norm of L1 norm) for matrices over a normed non-unital ring. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.linftyOpNonUnitalNormedRing = let __src := Matrix.linftyOpNonUnitalSemiNormedRing; NonUnitalNormedRing.mk ⋯ ⋯
Instances For
Normed ring instance (using sup norm of L1 norm) for matrices over a normed ring. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.linftyOpNormedRing = let __src := Matrix.linftyOpSemiNormedRing; NormedRing.mk ⋯ ⋯
Instances For
Normed algebra instance (using sup norm of L1 norm) for matrices over a normed algebra. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.linftyOpNormedAlgebra = let __src := Matrix.linftyOpNormedSpace; let __src_1 := Matrix.instAlgebra; NormedAlgebra.mk ⋯
Instances For
For a matrix over a field, the norm defined in this section agrees with the operator norm on
ContinuousLinearMap
s between function types (which have the infinity norm).
Alias of Matrix.linfty_opNNNorm_eq_opNNNorm
.
Alias of Matrix.linfty_opNorm_eq_opNorm
.
Alias of Matrix.linfty_opNNNorm_toMatrix
.
Alias of Matrix.linfty_opNorm_toMatrix
.
The Frobenius norm #
This is defined as $\|A\| = \sqrt{\sum_{i,j} \|A_{ij}\|^2}$. When the matrix is over the real or complex numbers, this norm is submultiplicative.
Seminormed group instance (using frobenius norm) for matrices over a seminormed group. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.frobeniusSeminormedAddCommGroup = inferInstanceAs (SeminormedAddCommGroup (PiLp 2 fun (_i : m) => PiLp 2 fun (_j : n) => α))
Instances For
Normed group instance (using frobenius norm) for matrices over a normed group. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.frobeniusNormedAddCommGroup = inferInstance
Instances For
This applies to the frobenius norm.
Normed space instance (using frobenius norm) for matrices over a normed space. Not declared as an instance because there are several natural choices for defining the norm of a matrix.
Equations
- Matrix.frobeniusNormedSpace = inferInstance
Instances For
Equations
- ⋯ = ⋯
Normed ring instance (using frobenius norm) for matrices over ℝ
or ℂ
. Not
declared as an instance because there are several natural choices for defining the norm of a
matrix.
Equations
- Matrix.frobeniusNormedRing = let __src := Matrix.frobeniusSeminormedAddCommGroup; let __src_1 := Matrix.instRing; NormedRing.mk ⋯ ⋯
Instances For
Normed algebra instance (using frobenius norm) for matrices over ℝ
or ℂ
. Not
declared as an instance because there are several natural choices for defining the norm of a
matrix.
Equations
- Matrix.frobeniusNormedAlgebra = let __src := Matrix.frobeniusNormedSpace; let __src_1 := Matrix.instAlgebra; NormedAlgebra.mk ⋯