Files
Entropyk/crates/solver/src/inverse/embedding.rs

600 lines
20 KiB
Rust

//! Residual embedding for One-Shot inverse control.
//!
//! This module implements the core innovation of Epic 5: embedding constraints
//! directly into the residual system for simultaneous solving with cycle equations.
//!
//! # Mathematical Foundation
//!
//! In One-Shot inverse control, constraints are added to the residual vector:
//!
//! $$r_{total} = [r_{cycle}, r_{constraints}]^T$$
//!
//! where:
//! - $r_{cycle}$ are the component residual equations
//! - $r_{constraints}$ are constraint residuals: $f(x) - y_{target}$
//!
//! The solver adjusts both edge states AND control variables simultaneously
//! to satisfy all equations.
//!
//! # Degrees of Freedom (DoF) Validation
//!
//! For a well-posed system:
//!
//! $$n_{equations} = n_{edge\_eqs} + n_{constraints}$$
//! $$n_{unknowns} = n_{edge\_unknowns} + n_{controls}$$
//!
//! The system is balanced when: $n_{equations} = n_{unknowns}$
//!
//! # Example
//!
//! ```rust,ignore
//! use entropyk_solver::inverse::{Constraint, ConstraintId, ComponentOutput};
//! use entropyk_solver::inverse::{BoundedVariable, BoundedVariableId};
//!
//! // Define constraint: superheat = 5K
//! let constraint = Constraint::new(
//! ConstraintId::new("superheat_control"),
//! ComponentOutput::Superheat { component_id: "evaporator".into() },
//! 5.0,
//! );
//!
//! // Define control variable: valve position
//! let valve = BoundedVariable::new(
//! BoundedVariableId::new("expansion_valve"),
//! 0.5, 0.0, 1.0,
//! )?;
//!
//! // Link constraint to control for One-Shot solving
//! system.add_constraint(constraint)?;
//! system.add_bounded_variable(valve)?;
//! system.link_constraint_to_control(
//! &ConstraintId::new("superheat_control"),
//! &BoundedVariableId::new("expansion_valve"),
//! )?;
//!
//! // Validate DoF before solving
//! system.validate_inverse_control_dof()?;
//! ```
use std::collections::HashMap;
use thiserror::Error;
use super::{BoundedVariableId, ConstraintId};
// ─────────────────────────────────────────────────────────────────────────────
// DoFError - Degrees of Freedom Validation Errors
// ─────────────────────────────────────────────────────────────────────────────
/// Errors during degrees of freedom validation for inverse control.
#[derive(Error, Debug, Clone, PartialEq)]
pub enum DoFError {
/// The system has more constraints than control variables.
#[error(
"Over-constrained system: {constraint_count} constraints but only {control_count} control variables \
(equations: {equation_count}, unknowns: {unknown_count})"
)]
OverConstrainedSystem {
constraint_count: usize,
control_count: usize,
equation_count: usize,
unknown_count: usize,
},
/// The system has fewer constraints than control variables (may still converge).
#[error(
"Under-constrained system: {constraint_count} constraints for {control_count} control variables \
(equations: {equation_count}, unknowns: {unknown_count})"
)]
UnderConstrainedSystem {
constraint_count: usize,
control_count: usize,
equation_count: usize,
unknown_count: usize,
},
/// The referenced constraint does not exist.
#[error("Constraint '{constraint_id}' not found when linking to control")]
ConstraintNotFound { constraint_id: ConstraintId },
/// The referenced bounded variable does not exist.
#[error("Bounded variable '{bounded_variable_id}' not found when linking to constraint")]
BoundedVariableNotFound {
bounded_variable_id: BoundedVariableId,
},
/// The constraint is already linked to a control variable.
#[error("Constraint '{constraint_id}' is already linked to control '{existing}'")]
AlreadyLinked {
constraint_id: ConstraintId,
existing: BoundedVariableId,
},
/// The control variable is already linked to another constraint.
#[error(
"Control variable '{bounded_variable_id}' is already linked to constraint '{existing}'"
)]
ControlAlreadyLinked {
bounded_variable_id: BoundedVariableId,
existing: ConstraintId,
},
}
// ─────────────────────────────────────────────────────────────────────────────
// ControlMapping - Constraint → Control Variable Mapping
// ─────────────────────────────────────────────────────────────────────────────
/// A mapping from a constraint to its control variable.
///
/// This establishes the relationship needed for One-Shot solving where
/// the solver adjusts the control variable to satisfy the constraint.
#[derive(Debug, Clone, PartialEq)]
pub struct ControlMapping {
/// The constraint to satisfy.
pub constraint_id: ConstraintId,
/// The control variable to adjust.
pub bounded_variable_id: BoundedVariableId,
/// Whether this mapping is active.
pub enabled: bool,
}
impl ControlMapping {
/// Creates a new control mapping.
pub fn new(constraint_id: ConstraintId, bounded_variable_id: BoundedVariableId) -> Self {
ControlMapping {
constraint_id,
bounded_variable_id,
enabled: true,
}
}
/// Creates a disabled mapping.
pub fn disabled(constraint_id: ConstraintId, bounded_variable_id: BoundedVariableId) -> Self {
ControlMapping {
constraint_id,
bounded_variable_id,
enabled: false,
}
}
/// Enables this mapping.
pub fn enable(&mut self) {
self.enabled = true;
}
/// Disables this mapping.
pub fn disable(&mut self) {
self.enabled = false;
}
}
// ─────────────────────────────────────────────────────────────────────────────
// InverseControlConfig - Configuration for Inverse Control
// ─────────────────────────────────────────────────────────────────────────────
/// Configuration for One-Shot inverse control.
///
/// Manages constraint-to-control-variable mappings for embedding constraints
/// into the residual system.
#[derive(Debug, Clone)]
pub struct InverseControlConfig {
/// Mapping from constraint ID to control variable ID.
constraint_to_control: HashMap<ConstraintId, BoundedVariableId>,
/// Mapping from control variable ID to constraint ID (reverse lookup).
control_to_constraint: HashMap<BoundedVariableId, ConstraintId>,
/// Whether inverse control is enabled globally.
enabled: bool,
/// Finite difference epsilon for numerical Jacobian computation.
/// Default is 1e-6, which balances numerical precision against floating-point rounding errors.
finite_diff_epsilon: f64,
}
impl Default for InverseControlConfig {
fn default() -> Self {
Self::new()
}
}
impl InverseControlConfig {
/// Default finite difference epsilon for numerical Jacobian computation.
pub const DEFAULT_FINITE_DIFF_EPSILON: f64 = 1e-6;
/// Creates a new empty inverse control configuration.
pub fn new() -> Self {
InverseControlConfig {
constraint_to_control: HashMap::new(),
control_to_constraint: HashMap::new(),
enabled: true,
finite_diff_epsilon: Self::DEFAULT_FINITE_DIFF_EPSILON,
}
}
/// Creates a disabled configuration.
pub fn disabled() -> Self {
InverseControlConfig {
constraint_to_control: HashMap::new(),
control_to_constraint: HashMap::new(),
enabled: false,
finite_diff_epsilon: Self::DEFAULT_FINITE_DIFF_EPSILON,
}
}
/// Returns the finite difference epsilon used for numerical Jacobian computation.
pub fn finite_diff_epsilon(&self) -> f64 {
self.finite_diff_epsilon
}
/// Sets the finite difference epsilon for numerical Jacobian computation.
///
/// # Panics
///
/// Panics if epsilon is non-positive.
pub fn set_finite_diff_epsilon(&mut self, epsilon: f64) {
assert!(epsilon > 0.0, "Finite difference epsilon must be positive");
self.finite_diff_epsilon = epsilon;
}
/// Returns whether inverse control is enabled.
pub fn is_enabled(&self) -> bool {
self.enabled
}
/// Enables inverse control.
pub fn enable(&mut self) {
self.enabled = true;
}
/// Disables inverse control.
pub fn disable(&mut self) {
self.enabled = false;
}
/// Returns the number of constraint-control mappings.
pub fn mapping_count(&self) -> usize {
self.constraint_to_control.len()
}
/// Links a constraint to a control variable.
///
/// # Errors
///
/// Returns `DoFError::AlreadyLinked` if the constraint is already linked.
/// Returns `DoFError::ControlAlreadyLinked` if the control is already linked.
pub fn link(
&mut self,
constraint_id: ConstraintId,
bounded_variable_id: BoundedVariableId,
) -> Result<(), DoFError> {
if let Some(existing) = self.constraint_to_control.get(&constraint_id) {
return Err(DoFError::AlreadyLinked {
constraint_id,
existing: existing.clone(),
});
}
if let Some(existing) = self.control_to_constraint.get(&bounded_variable_id) {
return Err(DoFError::ControlAlreadyLinked {
bounded_variable_id,
existing: existing.clone(),
});
}
self.constraint_to_control
.insert(constraint_id.clone(), bounded_variable_id.clone());
self.control_to_constraint
.insert(bounded_variable_id, constraint_id);
Ok(())
}
/// Unlinks a constraint from its control variable.
///
/// Returns the bounded variable ID that was linked, or `None` if not linked.
pub fn unlink_constraint(&mut self, constraint_id: &ConstraintId) -> Option<BoundedVariableId> {
if let Some(bounded_var_id) = self.constraint_to_control.remove(constraint_id) {
self.control_to_constraint.remove(&bounded_var_id);
Some(bounded_var_id)
} else {
None
}
}
/// Unlinks a control variable from its constraint.
///
/// Returns the constraint ID that was linked, or `None` if not linked.
pub fn unlink_control(
&mut self,
bounded_variable_id: &BoundedVariableId,
) -> Option<ConstraintId> {
if let Some(constraint_id) = self.control_to_constraint.remove(bounded_variable_id) {
self.constraint_to_control.remove(&constraint_id);
Some(constraint_id)
} else {
None
}
}
/// Returns the control variable linked to a constraint.
pub fn get_control(&self, constraint_id: &ConstraintId) -> Option<&BoundedVariableId> {
self.constraint_to_control.get(constraint_id)
}
/// Returns the constraint linked to a control variable.
pub fn get_constraint(&self, bounded_variable_id: &BoundedVariableId) -> Option<&ConstraintId> {
self.control_to_constraint.get(bounded_variable_id)
}
/// Returns an iterator over all constraint-to-control mappings.
pub fn mappings(&self) -> impl Iterator<Item = (&ConstraintId, &BoundedVariableId)> {
self.constraint_to_control.iter()
}
/// Returns an iterator over linked constraint IDs.
pub fn linked_constraints(&self) -> impl Iterator<Item = &ConstraintId> {
self.constraint_to_control.keys()
}
/// Returns an iterator over linked control variable IDs.
pub fn linked_controls(&self) -> impl Iterator<Item = &BoundedVariableId> {
self.control_to_constraint.keys()
}
/// Checks if a constraint is linked.
pub fn is_constraint_linked(&self, constraint_id: &ConstraintId) -> bool {
self.constraint_to_control.contains_key(constraint_id)
}
/// Checks if a control variable is linked.
pub fn is_control_linked(&self, bounded_variable_id: &BoundedVariableId) -> bool {
self.control_to_constraint.contains_key(bounded_variable_id)
}
/// Clears all mappings.
pub fn clear(&mut self) {
self.constraint_to_control.clear();
self.control_to_constraint.clear();
}
}
// ─────────────────────────────────────────────────────────────────────────────
// Tests
// ─────────────────────────────────────────────────────────────────────────────
#[cfg(test)]
mod tests {
use super::*;
fn make_constraint_id(s: &str) -> ConstraintId {
ConstraintId::new(s)
}
fn make_bounded_var_id(s: &str) -> BoundedVariableId {
BoundedVariableId::new(s)
}
#[test]
fn test_dof_error_display() {
let err = DoFError::OverConstrainedSystem {
constraint_count: 3,
control_count: 1,
equation_count: 10,
unknown_count: 8,
};
let msg = err.to_string();
assert!(msg.contains("3"));
assert!(msg.contains("1"));
assert!(msg.contains("10"));
assert!(msg.contains("8"));
assert!(msg.contains("Over-constrained"));
}
#[test]
fn test_dof_error_constraint_not_found() {
let err = DoFError::ConstraintNotFound {
constraint_id: make_constraint_id("test"),
};
assert!(err.to_string().contains("test"));
}
#[test]
fn test_dof_error_already_linked() {
let err = DoFError::AlreadyLinked {
constraint_id: make_constraint_id("c1"),
existing: make_bounded_var_id("v1"),
};
let msg = err.to_string();
assert!(msg.contains("c1"));
assert!(msg.contains("v1"));
}
#[test]
fn test_control_mapping_creation() {
let mapping = ControlMapping::new(
make_constraint_id("superheat"),
make_bounded_var_id("valve"),
);
assert_eq!(mapping.constraint_id.as_str(), "superheat");
assert_eq!(mapping.bounded_variable_id.as_str(), "valve");
assert!(mapping.enabled);
}
#[test]
fn test_control_mapping_disabled() {
let mapping = ControlMapping::disabled(
make_constraint_id("superheat"),
make_bounded_var_id("valve"),
);
assert!(!mapping.enabled);
}
#[test]
fn test_control_mapping_enable_disable() {
let mut mapping = ControlMapping::new(make_constraint_id("c"), make_bounded_var_id("v"));
mapping.disable();
assert!(!mapping.enabled);
mapping.enable();
assert!(mapping.enabled);
}
#[test]
fn test_inverse_control_config_new() {
let config = InverseControlConfig::new();
assert!(config.is_enabled());
assert_eq!(config.mapping_count(), 0);
}
#[test]
fn test_inverse_control_config_disabled() {
let config = InverseControlConfig::disabled();
assert!(!config.is_enabled());
}
#[test]
fn test_inverse_control_config_enable_disable() {
let mut config = InverseControlConfig::new();
config.disable();
assert!(!config.is_enabled());
config.enable();
assert!(config.is_enabled());
}
#[test]
fn test_inverse_control_config_link() {
let mut config = InverseControlConfig::new();
let result = config.link(make_constraint_id("c1"), make_bounded_var_id("v1"));
assert!(result.is_ok());
assert_eq!(config.mapping_count(), 1);
let control = config.get_control(&make_constraint_id("c1"));
assert!(control.is_some());
assert_eq!(control.unwrap().as_str(), "v1");
let constraint = config.get_constraint(&make_bounded_var_id("v1"));
assert!(constraint.is_some());
assert_eq!(constraint.unwrap().as_str(), "c1");
}
#[test]
fn test_inverse_control_config_link_already_linked_constraint() {
let mut config = InverseControlConfig::new();
config
.link(make_constraint_id("c1"), make_bounded_var_id("v1"))
.unwrap();
let result = config.link(make_constraint_id("c1"), make_bounded_var_id("v2"));
assert!(matches!(result, Err(DoFError::AlreadyLinked { .. })));
if let Err(DoFError::AlreadyLinked {
constraint_id,
existing,
}) = result
{
assert_eq!(constraint_id.as_str(), "c1");
assert_eq!(existing.as_str(), "v1");
}
}
#[test]
fn test_inverse_control_config_link_already_linked_control() {
let mut config = InverseControlConfig::new();
config
.link(make_constraint_id("c1"), make_bounded_var_id("v1"))
.unwrap();
let result = config.link(make_constraint_id("c2"), make_bounded_var_id("v1"));
assert!(matches!(result, Err(DoFError::ControlAlreadyLinked { .. })));
if let Err(DoFError::ControlAlreadyLinked {
bounded_variable_id,
existing,
}) = result
{
assert_eq!(bounded_variable_id.as_str(), "v1");
assert_eq!(existing.as_str(), "c1");
}
}
#[test]
fn test_inverse_control_config_unlink_constraint() {
let mut config = InverseControlConfig::new();
config
.link(make_constraint_id("c1"), make_bounded_var_id("v1"))
.unwrap();
let removed = config.unlink_constraint(&make_constraint_id("c1"));
assert!(removed.is_some());
assert_eq!(removed.unwrap().as_str(), "v1");
assert_eq!(config.mapping_count(), 0);
let removed_again = config.unlink_constraint(&make_constraint_id("c1"));
assert!(removed_again.is_none());
}
#[test]
fn test_inverse_control_config_unlink_control() {
let mut config = InverseControlConfig::new();
config
.link(make_constraint_id("c1"), make_bounded_var_id("v1"))
.unwrap();
let removed = config.unlink_control(&make_bounded_var_id("v1"));
assert!(removed.is_some());
assert_eq!(removed.unwrap().as_str(), "c1");
assert_eq!(config.mapping_count(), 0);
}
#[test]
fn test_inverse_control_config_is_linked() {
let mut config = InverseControlConfig::new();
assert!(!config.is_constraint_linked(&make_constraint_id("c1")));
assert!(!config.is_control_linked(&make_bounded_var_id("v1")));
config
.link(make_constraint_id("c1"), make_bounded_var_id("v1"))
.unwrap();
assert!(config.is_constraint_linked(&make_constraint_id("c1")));
assert!(config.is_control_linked(&make_bounded_var_id("v1")));
}
#[test]
fn test_inverse_control_config_mappings_iterator() {
let mut config = InverseControlConfig::new();
config
.link(make_constraint_id("c1"), make_bounded_var_id("v1"))
.unwrap();
config
.link(make_constraint_id("c2"), make_bounded_var_id("v2"))
.unwrap();
let mappings: Vec<_> = config.mappings().collect();
assert_eq!(mappings.len(), 2);
}
#[test]
fn test_inverse_control_config_clear() {
let mut config = InverseControlConfig::new();
config
.link(make_constraint_id("c1"), make_bounded_var_id("v1"))
.unwrap();
config
.link(make_constraint_id("c2"), make_bounded_var_id("v2"))
.unwrap();
config.clear();
assert_eq!(config.mapping_count(), 0);
}
}