# What commutes with diagonal matrix?

## What commutes with diagonal matrix?

The identity matrix commutes with all matrices. Every diagonal matrix commutes with all other diagonal matrices. Jordan blocks commute with upper triangular matrices that have the same value along bands. If the product of two symmetric matrices is symmetric, then they must commute.

### How do you find the diagonal of a matrix in R?

Matrix Diagonals

1. Description. Extract or replace the diagonal of a matrix, or construct a diagonal matrix.
2. Usage. diag(x = 1, nrow, ncol, names = TRUE) diag(x) <- value.
3. Arguments. x.
4. Details. diag has four distinct usages:
5. Value. If x is a matrix then diag(x) returns the diagonal of x .
6. Note.
7. References.

#### What does it mean if a matrix commutes?

The meaning of commuting matrices is as follows: Two matrices commute if the result of their product does not depend on the order of multiplication.

Is diagonal matrix multiplication commutative?

Multiplication of diagonal matrices is commutative: if A and B are diagonal, then C = AB = BA.

Do orthogonal and diagonal matrices commute?

Two normal matrices commute if and only if they are diagonalizable with respect to the same orthonormal basis.

## What do you mean by commuting?

to travel regularly over some distance, as from a suburb into a city and back: He commutes to work by train. to make substitution.

### How do you extract the diagonal elements of a matrix?

Description. D = diag( v ) returns a square diagonal matrix with the elements of vector v on the main diagonal. D = diag( v , k ) places the elements of vector v on the k th diagonal. k=0 represents the main diagonal, k>0 is above the main diagonal, and k<0 is below the main diagonal.

#### Does a matrix commute with its transpose?

More generally, an upper triangular matrix will commute with its transpose if and only if it is diagonal. If M commutes with its transpose, it is called a “normal” matrix.

Do rotation matrices commute?

Yes, general rotation matrices do not commute. The only exceptions are special (and generally not very useful) cases such as both rotations being about the same axis or one rotation being the identity.

Do orthogonal matrices commute?

## What is an example of commuting?

The definition of commute means to travel between home and work, or to change one thing for another. An example of to commute is someone taking the bus from their house to their office. An example of to commute is to reduce a one year jail sentence to time served.

### How do you use a commute?

Examples of commute in a Sentence Verb He commutes to work every day by train. She commutes 400 miles a week. The judge commuted his death sentence to life imprisonment.

#### What is diag () in R?

diag() function in R Language is used to construct a diagonal matrix. Syntax: diag(x, nrow, ncol) Parameters: x: value present as the diagonal elements. nrow, ncol: number of rows and columns in which elements are represented.

How do I extract specific rows from a matrix?

1. To extract any row from a matrix, use the colon operator in the second index position of your matrix. For example, consider the following:
2. “row1” is the first row of “A”, and “row2” is the second row.
3. For more on basic indexing, see:

Do skew symmetric matrices commute?

Each symmetric matrix that commutes with an skew-symmetric matrix is diago- nalizable. Proof. From proposition 2.19 we have that , and in this case, is clearly diagonalizable or has only two different eigenvalues, and one of them has geometric multiplicity of 2.

## How do you transpose a matrix in R?

The easiest way to transpose a matrix in R is to use the t() function. As previously, mentioned, you can use t(YourMatrix) to get the transpose of your matrix “YourMatrix”.

### Which rotations Cannot commute?

Rotations and translations do not commute. Translations and scales do not commute. Scales and rotations commute only in the special case when scaling by the same amount in all directions. In general the two operations do not commute.

#### Do rotation matrices in 2D always commute?

Two rotations in the plane are indeed commutative. However two rotations in 3d space are not commutative. It might help to pick up a die and try rotating it in different directions.

Is a diagonal matrix orthogonal?

Every diagonal matrix is orthogonal.

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