IsDiagonal

Tests if a matrix is diagonal.

Syntax

• IsDiagonal(A[, ε])

  • A is a matrix

  • ε is a positive number

Description

If A is a matrix, not necessarily square, then IsDiagonal(A, ε) is true iff i ≠ j implies A[i, j] = 0 (with epsilon ε).

Examples

A ≔ IdentityMatrix(100); B ≔ ❨❨4, 0, 0❩, ❨0, i, 0❩❩; C ≔ ❨❨5, 0❩, ❨0, 1❩, ❨0, 0❩❩;

∀({A, B, C}, (x ↦ IsDiagonal(x)))

true

See also

• IsAntidiagonal

• IsIdentity

• IsTriangular