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tensorneat-mend/algorithms/neat/genome/numpy/distance.py
2023-05-07 16:03:52 +08:00

115 lines
3.8 KiB
Python

from functools import partial
import numpy as np
from numpy.typing import NDArray
from algorithms.neat.genome.utils import flatten_connections, set_operation_analysis
EMPTY_NODE = np.full((1, 5), np.nan)
EMPTY_CON = np.full((1, 4), np.nan)
def distance(nodes1: NDArray, connections1: NDArray, nodes2: NDArray, connections2: NDArray) -> NDArray:
"""
Calculate the distance between two genomes.
nodes are a 2-d array with shape (N, 5), its columns are [key, bias, response, act, agg]
connections are a 3-d array with shape (2, N, N), axis 0 means [weights, enable]
"""
nd = node_distance(nodes1, nodes2) # node distance
# refactor connections
keys1, keys2 = nodes1[:, 0], nodes2[:, 0]
cons1 = flatten_connections(keys1, connections1)
cons2 = flatten_connections(keys2, connections2)
cd = connection_distance(cons1, cons2) # connection distance
return nd + cd
def node_distance(nodes1, nodes2, disjoint_coe=1., compatibility_coe=0.5):
node_cnt1 = np.sum(~np.isnan(nodes1[:, 0]))
node_cnt2 = np.sum(~np.isnan(nodes2[:, 0]))
max_cnt = np.maximum(node_cnt1, node_cnt2)
nodes = np.concatenate((nodes1, nodes2), axis=0)
keys = nodes[:, 0]
sorted_indices = np.argsort(keys, axis=0)
nodes = nodes[sorted_indices]
nodes = np.concatenate([nodes, EMPTY_NODE], axis=0) # add a nan row to the end
fr, sr = nodes[:-1], nodes[1:] # first row, second row
nan_mask = np.isnan(nodes[:, 0])
intersect_mask = (fr[:, 0] == sr[:, 0]) & ~nan_mask[:-1]
non_homologous_cnt = node_cnt1 + node_cnt2 - 2 * np.sum(intersect_mask)
nd = batch_homologous_node_distance(fr, sr)
nd = np.where(np.isnan(nd), 0, nd)
homologous_distance = np.sum(nd * intersect_mask)
val = non_homologous_cnt * disjoint_coe + homologous_distance * compatibility_coe
if max_cnt == 0: # consider the case that both genome has no gene
return 0
else:
return val / max_cnt
def connection_distance(cons1, cons2, disjoint_coe=1., compatibility_coe=0.5):
con_cnt1 = np.sum(~np.isnan(cons1[:, 2])) # weight is not nan, means the connection exists
con_cnt2 = np.sum(~np.isnan(cons2[:, 2]))
max_cnt = np.maximum(con_cnt1, con_cnt2)
cons = np.concatenate((cons1, cons2), axis=0)
keys = cons[:, :2]
sorted_indices = np.lexsort(keys.T[::-1])
cons = cons[sorted_indices]
cons = np.concatenate([cons, EMPTY_CON], axis=0) # add a nan row to the end
fr, sr = cons[:-1], cons[1:] # first row, second row
# both genome has such connection
intersect_mask = np.all(fr[:, :2] == sr[:, :2], axis=1) & ~np.isnan(fr[:, 2]) & ~np.isnan(sr[:, 2])
non_homologous_cnt = con_cnt1 + con_cnt2 - 2 * np.sum(intersect_mask)
cd = batch_homologous_connection_distance(fr, sr)
cd = np.where(np.isnan(cd), 0, cd)
homologous_distance = np.sum(cd * intersect_mask)
val = non_homologous_cnt * disjoint_coe + homologous_distance * compatibility_coe
if max_cnt == 0: # consider the case that both genome has no gene
return 0
else:
return val / max_cnt
def batch_homologous_node_distance(b_n1, b_n2):
res = []
for n1, n2 in zip(b_n1, b_n2):
d = homologous_node_distance(n1, n2)
res.append(d)
return np.stack(res, axis=0)
def batch_homologous_connection_distance(b_c1, b_c2):
res = []
for c1, c2 in zip(b_c1, b_c2):
d = homologous_connection_distance(c1, c2)
res.append(d)
return np.stack(res, axis=0)
def homologous_node_distance(n1, n2):
d = 0
d += np.abs(n1[1] - n2[1]) # bias
d += np.abs(n1[2] - n2[2]) # response
d += n1[3] != n2[3] # activation
d += n1[4] != n2[4]
return d
def homologous_connection_distance(c1, c2):
d = 0
d += np.abs(c1[2] - c2[2]) # weight
d += c1[3] != c2[3] # enable
return d