geosolver/TODO.txt

TODO/WISH LIST
--------------

Code: Some bits of the code are ugly:
    - vector module, matpy module and Numpy package, all offer similar
      functionality. Use only one, get rid of two. 
    - more documentation!

Speed: The solver is currently much too slow. The problem is the pattern
   matching algorithms that is used to find combinations of clusters that 
   can be rewritten/merged. Solutions:
    - incremental pattern matching system (work in progress)
    - compliled implementation (Psycho/C++/Haskell/???)

Rules: More rewrite rules to increase the problem domain:
    - need 3d rule: merge of 2 ridids with 2 shared points (hinge) + hog with angle not on hinge points  
    - larger subproblems (octahedron, variable radius spheres/cylinders)
    - new clusters types (N degrees of freedom)

Extentions:
    - implement geometry: lines, planes, spheres, cylinders, tori (mappings to
      cluster)
    - constraints on parameters (equality, algebraic constraints)
    - different variable domains (integers, reals, n-dimensional points,
      surfaces, volumes, logic variables, lists)

Easy of use:
    - move use_prototype flag to GeometricProblem (instead of in
      GeometricSolver)
    - check dimension of prototype points when adding to problem


BUGS:

- solver sometimes does not terminate - keeps adding merges where the result
  cluster and one of the original clusters merge again and again. Problem 
  likely that a source cluster should be removed (reducdant) but isn't. 

- following should be well-constraint, gives underconstrained (need extra rule/pattern) 
def diamond_3d():
    """creates a diamond shape with point 'v1'...'v4' in 3D with one solution"""
    L=10.0
    problem = GeometricProblem(dimension=3)
    problem.add_point('v1', vector([0.0, 0.0, 0.0]))
    problem.add_point('v2', vector([-5.0, 5.0, 0.0]))
    problem.add_point('v3', vector([5.0, 5.0, 0.0]))
    problem.add_point('v4', vector([0.0, 10.0, 0.0]))
    problem.add_constraint(DistanceConstraint('v1', 'v2', L))
    problem.add_constraint(DistanceConstraint('v1', 'v3', L))
    problem.add_constraint(DistanceConstraint('v2', 'v3', L))
    problem.add_constraint(DistanceConstraint('v2', 'v4', L))
    problem.add_constraint(DistanceConstraint('v3', 'v4', L))
    # this bit of code constrains the points v1...v4 in a plane with point p above v1 
    problem.add_point('p', vector([0.0, 0.0, 1.0]))
    problem.add_constraint(DistanceConstraint('v1', 'p', 1.0))
    problem.add_constraint(AngleConstraint('v2','v1','p', math.pi/2))
    problem.add_constraint(AngleConstraint('v3','v1','p', math.pi/2))
    problem.add_constraint(AngleConstraint('v4','v1','p', math.pi/2))

- when fixed (by swapping v1 and v3 in last bit of code)
  sometimes raises: 
       StandardError: more than one candidate prototype cluster for variable v2
  or: 
       FixConstraint(v2=[-5.0, 5.0, 0.0]) not satisfied
       FixConstraint(v1=[0.0, 0.0, 0.0]) not satisfied

- when solvin DAD type clusters, sometimes raises:
StandardError: cluster rigid#157388428(['v1', 'v2', 'v3']) already in clsolver

Debug output:

Solving....
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: a =   v3
triplet2dad: c =   v1
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: a =   v3
triplet2dad: c =   v1
triplet2dad: start
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: start
triplet2dad: b =  v2
triplet2dad: b in rigids
Traceback (most recent call last):
  File "test.py", line 971, in <module>
   t2d()
  File "test.py", line 968, in test2d
    test(dad_problem())
  File "test.py", line 780, in test
    solver = GeometricSolver(problem, use_prototype)
  File "/home/rick/lib/python/geosolver/geometric.py", line 294, in __init__
    self._add_constraint(con)
  File "/home/rick/lib/python/geosolver/geometric.py", line 486, in _add_constraint
    self.dr.add(hog)
  File "/home/rick/lib/python/geosolver/clsolver.py", line 79, in add
    self._process_new()
  File "/home/rick/lib/python/geosolver/clsolver.py", line 363, in _process_new
    self._add_method_complete(method)
  File "/home/rick/lib/python/geosolver/clsolver.py", line 487, in _add_method_complete
    self._add_cluster(output)
  File "/home/rick/lib/python/geosolver/clsolver.py", line 236, in _add_cluster
    raise StandardError, "cluster %s already in clsolver"%(str(newcluster))
StandardError: cluster rigid#157388428(['v1', 'v2', 'v3']) already in clsolver