Files
simpeg/SimPEG/Mesh/PointerTree.py
T
2015-11-04 14:23:36 -08:00

590 lines
19 KiB
Python

from SimPEG import np, sp, Utils, Solver
import matplotlib.pyplot as plt
import matplotlib
class ZCurve(object):
"""
The Z-order curve is generated by interleaving the bits of an offset.
See:
https://github.com/cortesi/scurve
Aldo Cortesi <aldo@corte.si>
"""
def __init__(self, dimension, bits):
"""
dimension: Number of dimensions
bits: The number of bits per co-ordinate. Total number of points is
2**(bits*dimension).
"""
self.dimension, self.bits = dimension, bits
def bitrange(self, x, width, start, end):
"""
Extract a bit range as an integer.
(start, end) is inclusive lower bound, exclusive upper bound.
"""
return x >> (width-end) & ((2**(end-start))-1)
def index(self, p):
p.reverse()
idx = 0
iwidth = self.bits * self.dimension
for i in range(iwidth):
bitoff = self.bits-(i/self.dimension)-1
poff = self.dimension-(i%self.dimension)-1
b = self.bitrange(p[poff], self.bits, bitoff, bitoff+1) << i
idx |= b
return idx
def point(self, idx):
p = [0]*self.dimension
iwidth = self.bits * self.dimension
for i in range(iwidth):
b = self.bitrange(idx, iwidth, i, i+1) << (iwidth-i-1)/self.dimension
p[i%self.dimension] |= b
p.reverse()
return p
def SortGrid(grid, offset=0):
"""
Sorts a grid by the x0 location.
"""
eps = 1e-7
def mycmp(c1,c2):
c1 = grid[c1-offset]
c2 = grid[c2-offset]
if c1.size == 2:
if np.abs(c1[1] - c2[1]) < eps:
return c1[0] - c2[0]
return c1[1] - c2[1]
elif c1.size == 3:
if np.abs(c1[2] - c2[2]) < eps:
if np.abs(c1[1] - c2[1]) < eps:
return c1[0] - c2[0]
return c1[1] - c2[1]
return c1[2] - c2[2]
class K(object):
def __init__(self, obj, *args):
self.obj = obj
def __lt__(self, other):
return mycmp(self.obj, other.obj) < 0
def __gt__(self, other):
return mycmp(self.obj, other.obj) > 0
def __eq__(self, other):
return mycmp(self.obj, other.obj) == 0
def __le__(self, other):
return mycmp(self.obj, other.obj) <= 0
def __ge__(self, other):
return mycmp(self.obj, other.obj) >= 0
def __ne__(self, other):
return mycmp(self.obj, other.obj) != 0
return sorted(range(offset,grid.shape[0]+offset), key=K)
class Tree(object):
def __init__(self, h_in, levels=3):
assert type(h_in) is list, 'h_in must be a list'
assert len(h_in) > 1, "len(h_in) must be greater than 1"
h = range(len(h_in))
for i, h_i in enumerate(h_in):
if type(h_i) in [int, long, float]:
# This gives you something over the unit cube.
h_i = np.ones(int(h_i))/int(h_i)
assert isinstance(h_i, np.ndarray), ("h[%i] is not a numpy array." % i)
assert len(h_i.shape) == 1, ("h[%i] must be a 1D numpy array." % i)
assert len(h_i) == 2**levels, "must make h and levels match"
h[i] = h_i[:] # make a copy.
self.h = h
self._levels = levels
self._levelBits = int(np.ceil(np.sqrt(levels)))+1
self.__dirty__ = True #: The numbering is dirty!
self._z = ZCurve(self.dim, 20)
self._treeInds = set()
self._treeInds.add(0)
@property
def levels(self): return self._levels
@property
def dim(self): return len(self.h)
@property
def nC(self): return len(self._treeInds)
@property
def nN(self):
self.number()
return self._nN
@property
def nF(self):
self.number()
return self._nF
@property
def nFx(self):
self.number()
return self._nFx
@property
def nFy(self):
self.number()
return self._nFy
@property
def nFz(self):
self.number()
return None if self.dim < 3 else self._nFz
@property
def nE(self):
self.number()
if self.dim == 2:
return self.nF
elif self.dim == 3:
return len(self.edges)
@property
def nEx(self):
self.number()
if self.dim == 2:
return self._nFy
elif self.dim == 3:
return self._nEx
@property
def nEy(self):
self.number()
if self.dim == 2:
return self._nFx
elif self.dim == 3:
return self._nEy
@property
def nEz(self):
self.number()
return None if self.dim < 3 else self._nEz
@property
def vol(self):
self.number()
return self._vol
@property
def area(self):
self.number()
return self._area
@property
def edge(self):
self.number()
if self.dim == 2:
return np.r_[self._area[self.nFx:], self._area[:self.nFx]]
@property
def _sortedInds(self):
if getattr(self, '__sortedInds', None) is None:
self.__sortedInds = sorted(self._treeInds)
return self.__sortedInds
@property
def permuteCC(self):
#TODO: cache these?
P = SortGrid(self.gridCC)
return sp.identity(self.nC).tocsr()[P,:]
@property
def permuteF(self):
#TODO: cache these?
P = SortGrid(self.gridFx)
P += SortGrid(self.gridFy, offset=self.nFx)
if self.dim == 3:
P += SortGrid(self.gridFz, offset=self.nFx+self.nFy)
return sp.identity(self.nF).tocsr()[P,:]
@property
def permuteE(self):
#TODO: cache these?
if self.dim == 2:
P = SortGrid(self.gridFy)
P += SortGrid(self.gridFx, offset=self.nEx)
return sp.identity(self.nE).tocsr()[P,:]
if self.dim == 3:
raise Exception()
def _structureChange(self):
if self.__dirty__: return
deleteThese = ['__sortedInds', '_gridCC', '_gridFx']
for p in deleteThese:
if hasattr(self, p): delattr(self, p)
self.__dirty__ = True
def _index(self, pointer):
assert len(pointer) is self.dim+1
assert pointer[-1] <= self.levels
x = self._z.index([p for p in pointer[:-1]]) # copy
return (x << self._levelBits) + pointer[-1]
def _pointer(self, index):
assert type(index) in [int, long]
n = index & (2**self._levelBits-1)
p = self._z.point(index >> self._levelBits)
return p + [n]
def __contains__(self, v):
if type(v) in [int, long]:
return v in self._treeInds
return self._index(v) in self._treeInds
def refine(self, function=None, recursive=True, cells=None):
cells = cells if cells is not None else sorted(self._treeInds)
recurse = []
for cell in cells:
p = self._pointer(cell)
do = function(self._cellC(cell)) > p[-1]
if do:
recurse += self._refineCell(cell)
if recursive and len(recurse) > 0:
self.refine(function=function, recursive=True, cells=recurse)
return recurse
def _refineCell(self, pointer):
self._structureChange()
pointer = self._asPointer(pointer)
ind = self._asIndex(pointer)
assert ind in self
h = self._levelWidth(pointer[-1])/2 # halfWidth
nL = pointer[-1] + 1 # new level
add = lambda p:p[0]+p[1]
added = []
def addCell(p):
i = self._index(p+[nL])
self._treeInds.add(i)
added.append(i)
addCell(map(add, zip(pointer[:-1], [0,0,0][:self.dim])))
addCell(map(add, zip(pointer[:-1], [h,0,0][:self.dim])))
addCell(map(add, zip(pointer[:-1], [0,h,0][:self.dim])))
addCell(map(add, zip(pointer[:-1], [h,h,0][:self.dim])))
if self.dim == 3:
addCell(map(add, zip(pointer[:-1], [0,0,h])))
addCell(map(add, zip(pointer[:-1], [h,0,h])))
addCell(map(add, zip(pointer[:-1], [0,h,h])))
addCell(map(add, zip(pointer[:-1], [h,h,h])))
self._treeInds.remove(ind)
return added
def _corsenCell(self, pointer):
self._structureChange()
raise Exception('Not yet implemented')
def _asPointer(self, ind):
if type(ind) in [int, long]:
return self._pointer(ind)
if type(ind) is list:
return ind
if isinstance(ind, np.ndarray):
return ind.tolist()
raise Exception
def _asIndex(self, pointer):
if type(pointer) in [int, long]:
return pointer
if type(pointer) is list:
return self._index(pointer)
raise Exception
def _parentPointer(self, pointer):
mod = self._levelWidth(pointer[-1]-1)
return [p - (p % mod) for p in pointer[:-1]] + [pointer[-1]-1]
def _cellN(self, p):
p = self._asPointer(p)
return [hi[:p[ii]].sum() for ii, hi in enumerate(self.h)]
def _cellH(self, p):
p = self._asPointer(p)
w = self._levelWidth(p[-1])
return [hi[p[ii]:p[ii]+w].sum() for ii, hi in enumerate(self.h)]
def _cellC(self, p):
return (np.array(self._cellH(p))/2.0 + self._cellN(p)).tolist()
def _levelWidth(self, level):
return 2**(self.levels - level)
def _isInsideMesh(self, pointer):
inside = True
for p in pointer[:-1]:
inside = inside and p >= 0 and p < 2**self.levels
return inside
def _getNextCell(self, ind, direction=0, positive=True):
"""
Returns a None, int, list, or nested list
The int is the cell number.
"""
pointer = self._asPointer(ind)
step = (1 if positive else -1) * self._levelWidth(pointer[-1])
nextCell = [p if ii is not direction else p + step for ii, p in enumerate(pointer)]
if not self._isInsideMesh(nextCell): return None
# it might be the same size as me?
if nextCell in self: return self._index(nextCell)
# it might be smaller than me?
if nextCell[-1] + 1 <= self.levels: # if I am not the smallest.
nextCell[-1] += 1
if not positive:
nextCell[direction] -= step/2 # Get the closer one
if nextCell in self: # there is at least one
hw = self._levelWidth(pointer[-1]) / 2
nextCell = np.array([p if ii is not direction else p + (step/2 if positive else 0) for ii, p in enumerate(pointer)])
if self.dim == 2:
if direction == 0: children = [0,0,1], [0,hw,1]
if direction == 1: children = [0,0,1], [hw,0,1]
elif self.dim == 3:
if direction == 0: children = [0,0,0,1], [0,hw,0,1], [0,0,hw,1], [0,hw,hw,1]
if direction == 1: children = [0,0,0,1], [hw,0,0,1], [0,0,hw,1], [hw,0,hw,1]
if direction == 2: children = [0,0,0,1], [hw,0,0,1], [0,hw,0,1], [hw,hw,0,1]
nextCells = []
for child in children:
nextCells.append(self._getNextCell(nextCell + child, direction=direction,positive=positive))
return nextCells
# it might be bigger than me?
return self._getNextCell(self._parentPointer(pointer),
direction=direction, positive=positive)
@property
def gridCC(self):
if getattr(self, '_gridCC', None) is None:
self._gridCC = np.zeros((len(self._treeInds),self.dim))
for ii, ind in enumerate(self._sortedInds):
p = self._asPointer(ind)
self._gridCC[ii, :] = self._cellC(p)
return self._gridCC
@property
def gridFx(self):
if getattr(self, '_gridFx', None) is None:
self.number()
return self._gridFx
@property
def gridFy(self):
if getattr(self, '_gridFy', None) is None:
self.number()
return self._gridFy
def _onSameLevel(self, i0, i1):
p0 = self._asPointer(i0)
p1 = self._asPointer(i1)
return p0[-1] == p1[-1]
def number(self, force=False):
if not self.__dirty__ and not force: return
facesX, facesY = [], []
areaX, areaY = [], []
hangingFacesX, hangingFacesY = [], []
faceXCount, faceYCount = -1, -1
fXm,fXp,fYm,fYp,fZm,fZp = range(6)
vol = []
def addXFace(count, p, positive=True):
n = self._cellN(p)
w = self._cellH(p)
areaX.append(w[1] if self.dim == 2 else w[1]*w[2])
if self.dim == 2:
facesX.append([n[0] + (w[0] if positive else 0), n[1] + w[1]/2.0])
elif self.dim == 3:
facesX.append([n[0] + (w[0] if positive else 0), n[1] + w[1]/2.0, n[2] + w[2]/2.0])
return count + 1
def addYFace(count, p, positive=True):
n = self._cellN(p)
w = self._cellH(p)
areaY.append(w[0] if self.dim == 2 else w[0]*w[2])
if self.dim == 2:
facesY.append([n[0] + w[0]/2.0, n[1] + (w[1] if positive else 0)])
elif self.dim == 3:
facesY.append([n[0] + w[0]/2.0, n[1] + (w[1] if positive else 0), n[2] + w[2]/2.0])
return count + 1
# c2cn = dict()
c2f = dict()
def gc2f(ind):
if ind in c2f: return c2f[ind]
c2f_ind = [list() for _ in xrange(2*self.dim)]
c2f[ind] = c2f_ind
return c2f_ind
def processCell(ind, faceCount, addFace, hangingFaces, DIR=0):
fM,fP=(0,1) if DIR == 0 else (2,3) if DIR == 1 else (4,5)
p = self._asPointer(ind)
if self._getNextCell(p, direction=DIR, positive=False) is None:
faceCount = addFace(faceCount, p, positive=False)
gc2f(ind)[fM] += [faceCount]
nextCell = self._getNextCell(p, direction=DIR)
# Add the next Xface
if nextCell is None:
# on the boundary
faceCount = addFace(faceCount, p)
gc2f(ind)[fP] += [faceCount]
elif type(nextCell) in [int, long] and self._onSameLevel(p,nextCell):
# same sized cell
faceCount = addFace(faceCount, p)
gc2f(ind)[fP] += [faceCount]
gc2f(nextCell)[fM] += [faceCount]
elif type(nextCell) in [int, long] and not self._onSameLevel(p,nextCell):
# the cell is bigger than me
faceCount = addFace(faceCount, p)
gc2f(ind)[fP] += [faceCount]
gc2f(nextCell)[fM] += [faceCount]
hangingFaces.append(faceCount)
elif type(nextCell) is list:
# the cell is smaller than me
# TODO: ensure that things are balanced.
p0 = self._pointer(nextCell[0])
p1 = self._pointer(nextCell[1])
faceCount = addFace(faceCount, p0, positive=False)
gc2f(nextCell[0])[fM] += [faceCount]
faceCount = addFace(faceCount, p1, positive=False)
gc2f(nextCell[1])[fM] += [faceCount]
gc2f(ind)[fP] += [faceCount-1,faceCount]
hangingFaces += [faceCount-1, faceCount]
return faceCount
for ii, ind in enumerate(self._sortedInds):
# c2cn[ind] = ii
vol.append(np.prod(self._cellH(ind)))
faceXCount = processCell(ind, faceXCount, addXFace, hangingFacesX, DIR=0)
faceYCount = processCell(ind, faceYCount, addYFace, hangingFacesY, DIR=1)
self._c2f = c2f
self._area = np.array(areaX + areaY)
self._vol = np.array(vol)
self._gridFx = np.array(facesX)
self._gridFy = np.array(facesY)
self._nC = len(self._sortedInds)
self._nFx = self._gridFx.shape[0]
self._nFy = self._gridFy.shape[0]
self._nF = self._nFx + self._nFy
self._hangingFacesX = hangingFacesX
self._hangingFacesY = hangingFacesY
self.__dirty__ = False
@property
def faceDiv(self):
# print self._c2f
if getattr(self, '_faceDiv', None) is None:
self.number()
# TODO: Preallocate!
I, J, V = [], [], []
PM = [-1,1]*self.dim # plus / minus
offset = [0,0,self.nFx,self.nFx]
for ii, ind in enumerate(self._sortedInds):
faces = self._c2f[ind]
for off, pm, face in zip(offset,PM,faces):
j = [_ + off for _ in face]
I += [ii]*len(j)
J += j
V += [pm]*len(j)
VOL = self.vol
D = sp.csr_matrix((V,(I,J)), shape=(self.nC, self.nF))
S = self.area
self._faceDiv = Utils.sdiag(1.0/VOL)*D*Utils.sdiag(S)
return self._faceDiv
def plotGrid(self, ax=None, showIt=False):
axOpts = {'projection':'3d'} if self.dim == 3 else {}
if ax is None:
ax = plt.subplot(111, **axOpts)
else:
assert isinstance(ax,matplotlib.axes.Axes), "ax must be an Axes!"
fig = ax.figure
for ind in self._sortedInds:
p = self._asPointer(ind)
n = self._cellN(p)
h = self._cellH(p)
x = [n[0] , n[0] + h[0], n[0] + h[0], n[0] , n[0]]
y = [n[1] , n[1] , n[1] + h[1], n[1] + h[1], n[1]]
z = [n[2] , n[2] , n[2] , n[2] , n[2]]
ax.plot(x,y, 'b-', zs=None if self.dim == 2 else z)
if self.dim == 3:
z = [n[2] + h[2], n[2] + h[2], n[2] + h[2], n[2] + h[2], n[2] + h[2]]
ax.plot(x,y, 'b-', zs=z)
sides = [0,0], [h[0],0], [0,h[1]], [h[0],h[1]]
for s in sides:
x = [n[0] + s[0], n[0] + s[0]]
y = [n[1] + s[1], n[1] + s[1]]
z = [n[2] , n[2] + h[2]]
ax.plot(x,y, 'b-', zs=z)
ax.plot(self.gridCC[[0,-1],0], self.gridCC[[0,-1],1], 'ro', zs=None if self.dim == 2 else self.gridCC[[0,-1],2])
ax.plot(self.gridCC[:,0], self.gridCC[:,1], 'r.', zs=None if self.dim == 2 else self.gridCC[:,2])
ax.plot(self.gridCC[:,0], self.gridCC[:,1], 'r:', zs=None if self.dim == 2 else self.gridCC[:,2])
ax.plot(self.gridFx[self._hangingFacesX,0], self.gridFx[self._hangingFacesX,1], 'gs', ms=10, mfc='none', mec='green', zs=None if self.dim == 2 else self.gridFx[self._hangingFacesX,2])
ax.plot(self.gridFx[:,0], self.gridFx[:,1], 'g>', zs=None if self.dim == 2 else self.gridFx[:,2])
ax.plot(self.gridFy[self._hangingFacesY,0], self.gridFy[self._hangingFacesY,1], 'gs', ms=10, mfc='none', mec='green', zs=None if self.dim == 2 else self.gridFy[self._hangingFacesY,2])
ax.plot(self.gridFy[:,0], self.gridFy[:,1], 'g^', zs=None if self.dim == 2 else self.gridFy[:,2])
if showIt:plt.show()
if __name__ == '__main__':
def function(xc):
r = xc - np.r_[0.5,0.5]
dist = np.sqrt(r.dot(r))
# if dist < 0.05:
# return 5
if dist < 0.1:
return 4
if dist < 0.3:
return 3
if dist < 1.0:
return 2
else:
return 0
T = Tree([4,4,4],levels=2)
T.refine(lambda xc:1)
T._refineCell([0,0,0,1])
T.plotGrid(showIt=True)