Measurement module
#include "diplib/chain_code.h"
dip::CovarianceMatrix class

A 2D covariance matrix for computation with 2D vertices.

The matrix is real, symmetric, positive semidefinite. See dip::Polygon::CovarianceMatrix for how to create a covariance matrix.

The elements stored are xx, xy and yy, with xx the top-left element, and xy both the off-diagonal elements, which are equal by definition.

Constructors, destructors, assignment and conversion operators

CovarianceMatrix() defaulted: Default-initialized covariance matrix is all zeros
CovarianceMatrix(dip::VertexFloat v) explicit: Construct a covariance matrix as the outer product of a vector and itself

auto xx() const -> dip::dfloat: Read matrix element
auto xy() const -> dip::dfloat: Read matrix element
auto yy() const -> dip::dfloat: Read matrix element
auto Det() const -> dip::dfloat: Compute determinant of matrix
auto Inv() const -> dip::CovarianceMatrix: Compute inverse of matrix
auto Project(dip::VertexFloat const& v) const -> dip::dfloat: Computes v’ * C * v, with v’ the transpose of v. This is a positive scalar if v is non-zero, because C (this matrix) is positive semidefinite.
auto Eig() const -> dip::CovarianceMatrix::Eigenvalues: Compute eigenvalues of matrix
auto Ellipse() const -> dip::CovarianceMatrix::EllipseParameters: Compute parameters of ellipse with same covariance matrix.

auto operator+=(dip::CovarianceMatrix const& other) -> dip::CovarianceMatrix&: Add other matrix to this matrix
auto operator*=(dip::dfloat d) -> dip::CovarianceMatrix&: Scale matrix
auto operator/=(dip::dfloat d) -> dip::CovarianceMatrix&: Scale matrix

Container for ellipse parameters