Files
tensorneat-mend/neat/genome/distance.py
wls2002 0cb2f9473d finish ask part of the algorithm;
use jax.lax.while_loop in graph algorithms and forward function;
fix "enabled not care" bug in forward
2023-06-25 00:26:52 +08:00

120 lines
3.9 KiB
Python

"""
Calculate the distance between two genomes.
The calculation method is the same as the distance calculation in NEAT-python.
See https://github.com/CodeReclaimers/neat-python/blob/master/neat/genome.py
"""
from typing import Dict
from jax import jit, vmap, Array
from jax import numpy as jnp
from .utils import EMPTY_NODE, EMPTY_CON
@jit
def distance(nodes1: Array, cons1: Array, nodes2: Array, cons2: Array, jit_config: Dict) -> Array:
"""
Calculate the distance between two genomes.
args:
nodes1: Array(N, 5)
cons1: Array(C, 4)
nodes2: Array(N, 5)
cons2: Array(C, 4)
returns:
distance: Array(, )
"""
nd = node_distance(nodes1, nodes2, jit_config) # node distance
cd = connection_distance(cons1, cons2, jit_config) # connection distance
return nd + cd
@jit
def node_distance(nodes1: Array, nodes2: Array, jit_config: Dict):
"""
Calculate the distance between nodes of two genomes.
"""
# statistics nodes count of two genomes
node_cnt1 = jnp.sum(~jnp.isnan(nodes1[:, 0]))
node_cnt2 = jnp.sum(~jnp.isnan(nodes2[:, 0]))
max_cnt = jnp.maximum(node_cnt1, node_cnt2)
# align homologous nodes
# this process is similar to np.intersect1d.
nodes = jnp.concatenate((nodes1, nodes2), axis=0)
keys = nodes[:, 0]
sorted_indices = jnp.argsort(keys, axis=0)
nodes = nodes[sorted_indices]
nodes = jnp.concatenate([nodes, EMPTY_NODE], axis=0) # add a nan row to the end
fr, sr = nodes[:-1], nodes[1:] # first row, second row
# flag location of homologous nodes
intersect_mask = (fr[:, 0] == sr[:, 0]) & ~jnp.isnan(nodes[:-1, 0])
# calculate the count of non_homologous of two genomes
non_homologous_cnt = node_cnt1 + node_cnt2 - 2 * jnp.sum(intersect_mask)
# calculate the distance of homologous nodes
hnd = vmap(homologous_node_distance)(fr, sr)
hnd = jnp.where(jnp.isnan(hnd), 0, hnd)
homologous_distance = jnp.sum(hnd * intersect_mask)
val = non_homologous_cnt * jit_config['compatibility_disjoint'] + homologous_distance * jit_config[
'compatibility_weight']
return jnp.where(max_cnt == 0, 0, val / max_cnt) # avoid zero division
@jit
def connection_distance(cons1: Array, cons2: Array, jit_config: Dict):
"""
Calculate the distance between connections of two genomes.
Similar process as node_distance.
"""
con_cnt1 = jnp.sum(~jnp.isnan(cons1[:, 0]))
con_cnt2 = jnp.sum(~jnp.isnan(cons2[:, 0]))
max_cnt = jnp.maximum(con_cnt1, con_cnt2)
cons = jnp.concatenate((cons1, cons2), axis=0)
keys = cons[:, :2]
sorted_indices = jnp.lexsort(keys.T[::-1])
cons = cons[sorted_indices]
cons = jnp.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 = jnp.all(fr[:, :2] == sr[:, :2], axis=1) & ~jnp.isnan(fr[:, 0])
non_homologous_cnt = con_cnt1 + con_cnt2 - 2 * jnp.sum(intersect_mask)
hcd = vmap(homologous_connection_distance)(fr, sr)
hcd = jnp.where(jnp.isnan(hcd), 0, hcd)
homologous_distance = jnp.sum(hcd * intersect_mask)
val = non_homologous_cnt * jit_config['compatibility_disjoint'] + homologous_distance * jit_config[
'compatibility_weight']
return jnp.where(max_cnt == 0, 0, val / max_cnt)
@jit
def homologous_node_distance(n1: Array, n2: Array):
"""
Calculate the distance between two homologous nodes.
"""
d = 0
d += jnp.abs(n1[1] - n2[1]) # bias
d += jnp.abs(n1[2] - n2[2]) # response
d += n1[3] != n2[3] # activation
d += n1[4] != n2[4] # aggregation
return d
@jit
def homologous_connection_distance(c1: Array, c2: Array):
"""
Calculate the distance between two homologous connections.
"""
d = 0
d += jnp.abs(c1[2] - c2[2]) # weight
d += c1[3] != c2[3] # enable
return d