Skip to main content
`Ctrl`+`K`

# petsc4py.typing.NormTypeSpec

petsc4py.typing.NormTypeSpec: TypeAlias = petsc4py.PETSc.NormType | None

  Norm type specification.

  Possible values include:

  - `NormType.NORM_1` The 1-norm: Σₙ abs(xₙ) for vectors, maxₙ (Σᵢ abs(xₙᵢ)) for matrices.

  - `NormType.NORM_2` The 2-norm: √(Σₙ xₙ²) for vectors, largest singular values for matrices.

  - `NormType.NORM_INFINITY` The ∞-norm: maxₙ abs(xₙ) for vectors, maxᵢ (Σₙ abs(xₙᵢ)) for matrices.

  - `NormType.NORM_FROBENIUS` The Frobenius norm: same as 2-norm for vectors, √(Σₙᵢ xₙᵢ²) for matrices.

  - `NormType.NORM_1_AND_2` Compute both `NormType.NORM_1` and `NormType.NORM_2`.

  - `None` as `NormType.NORM_2` for vectors, `NormType.NORM_FROBENIUS` for matrices.

  See also

  `PETSc.NormType`, `NormType`