def get_response_content(fs):
# read the tree
T, B, N = FtreeIO.newick_to_TBN(fs.tree)
leaves = Ftree.T_to_leaves(T)
internal = Ftree.T_to_internal_vertices(T)
# get the distinguished vertex of articulation
r = get_unique_vertex(N, fs.vertex)
if r not in internal:
raise ValueError(
'the distinguished vertex should have degree at least two')
# Partition the leaves with respect to the given root.
# Each set of leaves will eventually define a connected component.
R = Ftree.T_to_R_specific(T, r)
v_to_sinks = Ftree.R_to_v_to_sinks(R)
# break some edges
R_pruned = set(R)
neighbors = Ftree.T_to_v_to_neighbors(T)[r]
for adj in neighbors:
R_pruned.remove((r, adj))
T_pruned = Ftree.R_to_T(R_pruned)
# get the leaf partition
ordered_leaves = []
leaf_lists = []
for adj in neighbors:
R_subtree = Ftree.T_to_R_specific(T_pruned, adj)
C = sorted(b for a, b in R_subtree if b not in v_to_sinks)
ordered_leaves.extend(C)
leaf_lists.append(C)
# define the vertices to keep and those to remove
keepers = ordered_leaves + [r]
# get the schur complement
L_schur = Ftree.TB_to_L_schur(T, B, keepers)
# get principal submatrices of the schur complement
principal_matrices = []
accum = 0
for component_leaves in leaf_lists:
n = len(component_leaves)
M = L_schur[accum:accum+n, accum:accum+n]
principal_matrices.append(M)
accum += n
# write the report
out = StringIO()
print >> out, 'algebraic connectivity:'
print >> out, get_algebraic_connectivity(T, B, leaves)
print >> out
print >> out
print >> out, 'perron values:'
print >> out
for M, leaf_list in zip(principal_matrices, leaf_lists):
value = scipy.linalg.eigh(M, eigvals_only=True)[0]
name_list = [N[v] for v in leaf_list]
print >> out, name_list
print >> out, value
print >> out
return out.getvalue()
def get_response_content(fs):
# read the tree
T, B, N = FtreeIO.newick_to_TBN(fs.tree)
leaves = Ftree.T_to_leaves(T)
internal = Ftree.T_to_internal_vertices(T)
# get the valuations with harmonic extensions
w, V = Ftree.TB_to_harmonic_extension(T, B, leaves, internal)
# get the Fiedler valuations with harmonic extensions
h = V[:, 0]
# check for vertices with small valuations
eps = 1e-8
if any(abs(x) < x for x in h):
raise ValueError('the tree has no clear harmonic Fiedler point')
# find the edge contining the harmonic Fiedler point
v_to_val = dict((v, h[i]) for i, v in enumerate(leaves + internal))
d_edges = [(a, b) for a, b in T if v_to_val[a] * v_to_val[b] < 0]
if len(d_edges) != 1:
raise ValueError('expected the point to fall clearly on a single edge')
d_edge = d_edges[0]
a, b = d_edge
# find the proportion along the directed edge
t = v_to_val[a] / (v_to_val[a] - v_to_val[b])
# find the distance from the new root to each endpoint vertices
u_edge = frozenset(d_edge)
d = B[u_edge]
da = t * d
db = (1 - t) * d
# create the new tree
r = max(Ftree.T_to_order(T)) + 1
N[r] = fs.root_name
T.remove(u_edge)
del B[u_edge]
ea = frozenset((r, a))
eb = frozenset((r, b))
T.add(ea)
T.add(eb)
B[ea] = da
B[eb] = db
# add a new leaf with arbitrary branch length
leaf = r + 1
N[leaf] = fs.leaf_name
u_edge = frozenset((r, leaf))
T.add(u_edge)
B[u_edge] = 1.0
# get the best branch length to cause eigenvalue multiplicity
blen = scipy.optimize.golden(get_gap, (T, B, u_edge),
full_output=False,
tol=1e-12)
B[u_edge] = blen
# return the string representation of the new tree
R = Ftree.T_to_R_specific(T, r)
return FtreeIO.RBN_to_newick(R, B, N)
def get_response_content(fs):
# read the tree
T, B, N = FtreeIO.newick_to_TBN(fs.tree)
leaves = Ftree.T_to_leaves(T)
internal = Ftree.T_to_internal_vertices(T)
# get the valuations with harmonic extensions
w, V = Ftree.TB_to_harmonic_extension(T, B, leaves, internal)
# get the Fiedler valuations with harmonic extensions
h = V[:, 0]
# check for vertices with small valuations
eps = 1e-8
if any(abs(x) < x for x in h):
raise ValueError('the tree has no clear harmonic Fiedler point')
# find the edge contining the harmonic Fiedler point
v_to_val = dict((v, h[i]) for i, v in enumerate(leaves + internal))
d_edges = [(a, b) for a, b in T if v_to_val[a] * v_to_val[b] < 0]
if len(d_edges) != 1:
raise ValueError('expected the point to fall clearly on a single edge')
d_edge = d_edges[0]
a, b = d_edge
# find the proportion along the directed edge
t = v_to_val[a] / (v_to_val[a] - v_to_val[b])
# find the distance from the new root to each endpoint vertices
u_edge = frozenset(d_edge)
d = B[u_edge]
da = t * d
db = (1 - t) * d
# create the new tree
r = max(Ftree.T_to_order(T)) + 1
T.remove(u_edge)
del B[u_edge]
ea = frozenset((r, a))
eb = frozenset((r, b))
T.add(ea)
T.add(eb)
B[ea] = da
B[eb] = db
R = Ftree.T_to_R_specific(T, r)
# return the string representation of the new tree
return FtreeIO.RBN_to_newick(R, B, N)
def set_root(self, v):
"""
This is slow, probably as a result of the design.
"""
self.R = Ftree.T_to_R_specific(Ftree.R_to_T(self.R), v)
self.v_to_source = Ftree.R_to_v_to_source(self.R)
