Enum ResponseManifold 

pub enum ResponseManifold {
    Spd {
        n: usize,
    },
    Grassmann {
        k: usize,
        n: usize,
    },
    Stiefel {
        k: usize,
        n: usize,
    },
    Poincare {
        dim: usize,
        curvature: f64,
    },
    ConstantCurvature {
        dim: usize,
        kappa: f64,
    },
}

A fittable curved response geometry. Each variant carries the shape the user requested; the embedding/ambient flat dimension is fixed by that shape and is the column count of the values matrix the caller supplies.

Variants

Spd

Symmetric positive-definite n×n matrices, flattened row-major to n² ambient coordinates (the layout SpdManifold uses).

Fields

n: usize

Grassmann

k-dimensional subspaces of ℝⁿ, represented by an orthonormal n×k frame flattened to n·k ambient coordinates.

Fields

k: usize

n: usize

Stiefel

Orthonormal k-frames in ℝⁿ, flattened to n·k ambient coordinates.

Fields

k: usize

n: usize

Poincare

The Poincaré ball of dimension d with curvature κ < 0.

Fields

dim: usize

curvature: f64

ConstantCurvature

Constant-curvature manifold M_κ of dimension d with curvature κ (any finite real value). κ > 0 → spherical, κ = 0 → flat (Euclidean up to scale), κ < 0 → hyperbolic (Poincaré ball). Unlike Poincare, which fixes κ < 0, this variant accepts any curvature including zero and positive values, and is the target for curvature-as-estimand fits where κ̂ is optimized over all of ℝ (#1104).

Fields

dim: usize

kappa: f64

Implementations

impl ResponseManifold

pub fn resolve( kind: &str, n: Option<usize>, k: Option<usize>, dim: Option<usize>, curvature: Option<f64>, ) -> Result<Self, String>

Resolve a lower-cased geometry label and its shape parameters into a response manifold. Shape parameters are passed positionally exactly as the FFI marshals them; absent/zero values are rejected here so the error surfaces at selection time rather than mid-fit.

• "spd" needs n (matrix side).
• "grassmann" / "stiefel" need k and n with 1 ≤ k ≤ n.
• "poincare" needs dim and a strictly negative curvature.

pub fn parse(label: &str, cols: usize) -> Result<Self, String>

Parse a user-facing response_geometry label, magic-by-default: the head is the geometry name, an optional parenthesised key=value list carries shape parameters, and anything not given is inferred from the ambient column count cols of the response matrix.

Recognised forms (case-insensitive, whitespace tolerant):

• "spd" — n = √cols (must be a perfect square).
• "grassmann(k=2)" or "grassmann(k=2,n=5)" — n defaults to cols / k; k is required (it cannot be inferred from n·k).
• "stiefel(k=2)" / "stiefel(k=2,n=5)" — same inference as Grassmann.
• "poincare" or "poincare(curvature=-0.5)" — dim = cols; curvature defaults to -1.0.

This is the single mapping from the formula-DSL string to a constructed response manifold; the FFI passes the raw label straight through.

pub fn canonical_label(&self) -> String

Canonical, fully-specified label echoed back to the caller (mirrors the way the sphere/simplex dispatch reports its resolved coordinate label).

pub fn ambient_dim(&self) -> usize

Ambient (flattened) coordinate count: the column width of the values matrix and the base vector.

Trait Implementations

impl Clone for ResponseManifold

fn clone(&self) -> ResponseManifold

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ResponseManifold

impl Debug for ResponseManifold

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

Formats the value using the given formatter.

impl PartialEq for ResponseManifold

fn eq(&self, other: &ResponseManifold) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ResponseManifold