rref

Gauss-Jordan elimination.

Syntax

• R = rref(A)
• R = rref(A, tol)
• [R, p] = rref(A)
• [R, p] = rref(A, tol)

Input argument

• A - input matrix (double or single)
• tol - tolerance: scalar or max(rows, cols) _ eps(class(A)) _ norm(A, inf) (default)

Output argument

• R - a matrix: reduced row echelon form of A.
• p - a vector: nonzero pivot columns.

Description

R = rref(A) returns the reduced row echelon form of A.

[R, p] = rref(A) returns also the nonzero pivots p.

Bibliography

https://en.wikipedia.org/wiki/Gaussian_elimination

Example

A = [magic(4), eye(4)]
[R, p] = rref(A)

See also

rank.

History

Author

Allan CORNET