linsolve

Solve a linear system with optional structure hints.

Syntax

X = linsolve(A, B)
X = linsolve(A, B, opts)

Description

Solves A*X = B for X. Equivalent to MATLAB’s backslash A\B for the simple form, but accepts an opts struct with hints about A’s structure (LT lower-triangular, UT upper-triangular, SYM symmetric, POSDEF positive-definite, RECT rectangular least-squares, TRANSA apply transpose).

With hints, LAPACK uses the appropriate specialized solver — substantially faster than the generic LU pivoted solver when the structure is known.

Examples

A = magic(3); b = [1; 2; 3];
x = linsolve(A, b)       % solves A*x = b
norm(A*x - b)            % near-zero

See also

• lu — LU decomposition (with partial pivoting).
• qr — QR decomposition.
• chol — Cholesky factorization of a Hermitian positive-definite matrix.
• inv — Matrix inverse.