pub fn jacobian(
graph: &FitGraphSpec,
params_flat: &HashMap<String, f64>,
x: &[f64],
) -> Result<DMatrix<f64>, CoreError>Expand description
Compute the full analytical Jacobian matrix for use by the solver.
Returns a matrix of shape [n_points × n_free_params].
Free parameters are ordered by (node_id alphabetically, then param order
as declared by the model’s param_names()).
§Errors
Returns CoreError::Eval if: the graph fails to compile (see
CompiledGraph::compile); params_flat is missing a required
"node_id.param_name" entry; x.len() is not an exact multiple of the
graph’s coordinate dimensionality; or a node’s dataset_index is out of
range for the compiled dataset_offsets.