Files
solver/kindred_solver/params.py
forbes-0023 64b1e24467 feat(solver): compile symbolic Jacobian to flat Python for fast evaluation
Add a code generation pipeline that compiles Expr DAGs into flat Python
functions, eliminating recursive tree-walk dispatch in the Newton-Raphson
inner loop.

Key changes:
- Add to_code() method to all 11 Expr node types (expr.py)
- New codegen.py module with CSE (common subexpression elimination),
  sparsity detection, and compile()/exec() compilation pipeline
- Add ParamTable.env_ref() to avoid dict copies per iteration (params.py)
- Newton and BFGS solvers accept pre-built jac_exprs and compiled_eval
  to avoid redundant diff/simplify and enable compiled evaluation
- count_dof() and diagnostics accept pre-built jac_exprs
- solver.py builds symbolic Jacobian once, compiles once, passes to all
  consumers (_monolithic_solve, count_dof, diagnostics)
- Automatic fallback: if codegen fails, tree-walk eval is used

Expected performance impact:
- ~10-20x faster Jacobian evaluation (no recursive dispatch)
- ~2-5x additional from CSE on quaternion-heavy systems
- ~3x fewer entries evaluated via sparsity detection
- Eliminates redundant diff().simplify() in DOF/diagnostics
2026-02-21 11:22:36 -06:00

115 lines
3.7 KiB
Python

"""Parameter table mapping named variables to Expr Var nodes and current values."""
from __future__ import annotations
from typing import Dict, List
import numpy as np
from .expr import Var
class ParamTable:
"""Central registry of solver variables.
Each parameter has a name, a current numeric value, an associated
:class:`Var` expression node, and a fixed/free flag. Grounded
body parameters are marked fixed so the pre-pass can substitute
them as constants.
"""
def __init__(self):
self._vars: Dict[str, Var] = {}
self._values: Dict[str, float] = {}
self._fixed: set[str] = set()
self._free_order: List[str] = [] # insertion-ordered free names
def add(self, name: str, value: float = 0.0, fixed: bool = False) -> Var:
"""Create a parameter and return its Var node."""
if name in self._vars:
raise ValueError(f"Duplicate parameter: {name}")
v = Var(name)
self._vars[name] = v
self._values[name] = value
if fixed:
self._fixed.add(name)
else:
self._free_order.append(name)
return v
def get_var(self, name: str) -> Var:
return self._vars[name]
def is_fixed(self, name: str) -> bool:
return name in self._fixed
def fix(self, name: str):
"""Mark a parameter as fixed and remove it from the free list."""
self._fixed.add(name)
if name in self._free_order:
self._free_order.remove(name)
def unfix(self, name: str):
"""Restore a fixed parameter to free status."""
if name in self._fixed:
self._fixed.discard(name)
if name not in self._free_order:
self._free_order.append(name)
def get_env(self) -> Dict[str, float]:
"""Return a snapshot of all current values (for Expr.eval)."""
return dict(self._values)
def env_ref(self) -> Dict[str, float]:
"""Return a direct reference to the internal values dict.
Faster than :meth:`get_env` (no copy). Safe when the caller
only reads during evaluation and mutates via :meth:`set_free_vector`.
"""
return self._values
def free_names(self) -> List[str]:
"""Return ordered list of free (non-fixed) parameter names."""
return list(self._free_order)
def n_free(self) -> int:
return len(self._free_order)
def get_value(self, name: str) -> float:
return self._values[name]
def set_value(self, name: str, value: float):
self._values[name] = value
def get_free_vector(self) -> np.ndarray:
"""Current free-parameter values as a 1-D array."""
return np.array([self._values[n] for n in self._free_order], dtype=np.float64)
def set_free_vector(self, vec: np.ndarray):
"""Bulk-update free parameters from a 1-D array."""
for i, name in enumerate(self._free_order):
self._values[name] = float(vec[i])
def snapshot(self) -> Dict[str, float]:
"""Capture current values as a checkpoint."""
return dict(self._values)
def restore(self, snap: Dict[str, float]):
"""Restore parameter values from a checkpoint."""
for name, val in snap.items():
if name in self._values:
self._values[name] = val
def movement_cost(
self,
start: Dict[str, float],
weights: Dict[str, float] | None = None,
) -> float:
"""Weighted sum of squared displacements from start."""
cost = 0.0
for name in self._free_order:
w = weights.get(name, 1.0) if weights else 1.0
delta = self._values[name] - start.get(name, self._values[name])
cost += delta * delta * w
return cost