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boundary-aware-centrality/diff_model_comparison.py

149 lines
5.2 KiB
Python

import math
import matplotlib.pyplot as plt
import numpy as np
from graph_tool.all import *
from src import centrality
from src import plot
from src import fitting
def leverage(g, weight):
# VertexPropertyMap
vp = g.new_vertex_property("double")
for v in g.vertices():
li = 0.0
neighbours = g.get_all_neighbours(v)
ki = len(neighbours)
# sum
for nv in neighbours:
other_neighbours = g.get_all_neighbours(nv)
kj = len(other_neighbours)
li += (ki - kj) / (ki + kj)
li /= ki
vp[v] = li
return vp
def random_graph(n=5000, seed=None):
"""
Uniformly random point cloud generation.
`n` [int] Number of points to generate. Default 5000 seems like a good starting point in point density and corresponding runtime for the subsequent calculations.
@return [numpy.ndarray] Array of shape(n, 2) containing the coordinates for each point of the generated point cloud.
"""
if seed is None:
import secrets
seed = secrets.randbits(128)
rng = np.random.default_rng(seed=seed)
return rng.random((n, 2)), seed
def sub_spatial_graph(adata, percentage):
sub_adata = np.array([])
distance_of_center = 0.5 * percentage
for point in adata:
if point[0] > 0.5 - distance_of_center and point[0] <= 0.5 + distance_of_center:
if point[1] > 0.5 - distance_of_center and point[1] <= 0.5 + distance_of_center:
sub_adata = np.append(sub_adata, [point[0], point[1]])
sub_adata = sub_adata.reshape(sub_adata.shape[0] // 2, 2)
return spatial_graph(sub_adata)
def spatial_graph(adata):
"""
Generate the spatial graph using delaunay for the given `adata`.
`adata` will contain the calculated spatial graph contents in the keys
adata.obsm['spatial']` in case the `adata` is created from a dataset of *squidpy*.
@return [Graph] generated networkx graph from adata.obsp['spatial_distances']
"""
g, pos = graph_tool.generation.triangulation(adata, type="delaunay")
g.vp["pos"] = pos
weight = g.new_edge_property("double")
for e in g.edges():
weight[e] = math.sqrt(sum(map(abs, pos[e.source()].a - pos[e.target()].a)))**2
return g, weight
def apply(g, weight, convex_hull, ax, method, method_name):
# calculate centrality values
vp = None
if method_name == "Betweeness":
vp, ep = method(g, weight=weight)
elif method_name == "Eigenvector":
ep, vp = method(g, weight=weight)
elif method_name == "Hits":
ep, vp, hub_centrality = method(g, weight=weight)
else:
vp = method(g, weight=weight)
vp.a = np.nan_to_num(vp.a) # correct floating point values
# normalization
min_val, max_val = vp.a.min(), vp.a.max()
vp.a = (vp.a - min_val) / (max_val - min_val)
# generate model based on convex hull and associated centrality values
quantification = plot.quantification_data(g, vp, convex_hull)
# optimize model's piece-wise linear function
d = quantification[:, 0]
C = quantification[:, 1]
m_opt, c0_opt, b_opt, aic_opt = fitting.fit_piece_wise_linear(d, C)
# TODO
# should this be part of the plotting function itself, it should not be necessary for me to do this
d_curve = np.linspace(min(d), max(d), 500)
C_curve = np.piecewise(
d_curve,
[d_curve <= b_opt, d_curve > b_opt],
[lambda x: m_opt * x + c0_opt, lambda x: m_opt * b_opt + c0_opt]
)
# plot model containing modeled piece-wise linear function
plot.quantification_plot(ax, quantification, d_curve, C_curve, method_name, aic_opt)
#
# - Create a random point cloud and calculate a triangulation on it
# - For that graph calculate the convex hull
# - Draw the graph with the convex hull
# - For each centrality measure
# - apply centrality measure to the next axis
# - Draw the corresponding resulting models into a grid
#
points, seed = random_graph(n=5000)
g, weight = spatial_graph(points)
g = GraphView(g)
# calculate convex hull
convex_hull = centrality.convex_hull(g)
# plot graph with convex_hull
fig_graph, ax_graph = plt.subplots(figsize=(15, 12))
# draw without any centrality measure `vp`
vp = g.new_vertex_property("double")
plot.graph_plot(fig_graph, ax_graph, g, vp, convex_hull, f"Pointcloud (seed: {seed})")
fig_graph.savefig("point_cloud_diff_comparison_5000_pagerank_leverage.svg", format='svg')
fig = plt.figure(figsize=(15, 12))
row1, row2 = fig.subplots(2, 2)
ax1, ax2 = row1
apply(g, weight, convex_hull, ax1, pagerank, "PageRank")
apply(g, weight, convex_hull, ax2, leverage, "Leverage")
g_sub, weight_sub = sub_spatial_graph(points, 0.5)
g_sub = GraphView(g_sub)
convex_hull = centrality.convex_hull(g_sub)
# plot graph with convex_hull
fig_graph, ax_graph = plt.subplots(figsize=(15, 12))
# draw without any centrality measure `vp`
vp = g_sub.new_vertex_property("double")
plot.graph_plot(fig_graph, ax_graph, g_sub, vp, convex_hull, f"Pointcloud (50% of original)")
fig_graph.savefig("point_cloud_diff_comparison_5000_sub_pagerank_leverage.svg", format='svg')
ax1, ax2 = row2
apply(g_sub, weight_sub, convex_hull, ax1, pagerank, "PageRank")
apply(g_sub, weight_sub, convex_hull, ax2, leverage, "Leverage")
fig.savefig(f"model_diff_comparison_5000_pagerank_leverage.svg", format='svg')