Struct QuadraticTerms 

pub struct QuadraticTerms {
    pub hessian: Vec<(VarId, VarId, f64)>,
    pub linear: Vec<(VarId, f64)>,
    pub constant: f64,
}

Quadratic decomposition of an expression: its Hessian, gradient-linear part, and constant.

For a degree-<= 2 polynomial f(x), this holds the exact Taylor data

f(x) = constant + sum_i linear_i * x_i + 0.5 * x' Q x

where Q is the (constant) Hessian. Returned by extract_quadratic.

Fields

hessian: Vec<(VarId, VarId, f64)>

Lower-triangle Hessian entries (row, col, h) with row >= col, where h = partial^2 f / partial x_row partial x_col. Diagonal entries are the full second derivative, so a * x^2 yields (x, x, 2a). This matches the 0.5 * x' Q x convention used by QP solvers.

linear: Vec<(VarId, f64)>

Linear coefficients (var, coeff), the gradient of f at the origin.

constant: f64

The constant term f(0).

Trait Implementations

impl Clone for QuadraticTerms

fn clone(&self) -> QuadraticTerms

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for QuadraticTerms

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for QuadraticTerms

fn default() -> QuadraticTerms

Returns the “default value” for a type.