Files
tensorneat-mend/algorithm/neat/ga/mutate.py
2023-08-02 13:26:01 +08:00

187 lines
6.9 KiB
Python

from typing import Tuple
import jax
from jax import Array, numpy as jnp, vmap
from config import NeatConfig
from core import State, Gene, Genome
from utils import check_cycles, fetch_random, fetch_first, I_INT, unflatten_conns
def mutate(config: NeatConfig, gene: Gene, state: State, randkey, genome: Genome, new_node_key):
"""
Mutate a population of genomes
"""
k1, k2 = jax.random.split(randkey)
genome = mutate_structure(config, gene, state, k1, genome, new_node_key)
genome = mutate_values(gene, state, randkey, genome)
return genome
def mutate_structure(config: NeatConfig, gene: Gene, state: State, randkey, genome: Genome, new_node_key):
def mutate_add_node(key_, genome_: Genome):
i_key, o_key, idx = choice_connection_key(key_, genome_.conns)
def nothing():
return genome_
def successful_add_node():
# disable the connection
new_genome = genome_.update_conns(genome_.conns.at[idx, 2].set(False))
# add a new node
new_genome = new_genome.add_node(new_node_key, gene.new_node_attrs(state))
# add two new connections
new_genome = new_genome.add_conn(i_key, new_node_key, True, gene.new_conn_attrs(state))
new_genome = new_genome.add_conn(new_node_key, o_key, True, gene.new_conn_attrs(state))
return new_genome
# if from_idx == I_INT, that means no connection exist, do nothing
return jax.lax.cond(idx == I_INT, nothing, successful_add_node)
def mutate_delete_node(key_, genome_: Genome):
# TODO: Do we really need to delete a node?
# randomly choose a node
key, idx = choice_node_key(key_, genome_.nodes, state.input_idx, state.output_idx,
allow_input_keys=False, allow_output_keys=False)
def nothing():
return genome_
def successful_delete_node():
# delete the node
new_genome = genome_.delete_node_by_pos(idx)
# delete all connections
new_conns = jnp.where(((new_genome.conns[:, 0] == key) | (new_genome.conns[:, 1] == key))[:, None],
jnp.nan, new_genome.conns)
return new_genome.update_conns(new_conns)
return jax.lax.cond(idx == I_INT, nothing, successful_delete_node)
def mutate_add_conn(key_, genome_: Genome):
# randomly choose two nodes
k1_, k2_ = jax.random.split(key_, num=2)
i_key, from_idx = choice_node_key(k1_, genome_.nodes, state.input_idx, state.output_idx,
allow_input_keys=True, allow_output_keys=True)
o_key, to_idx = choice_node_key(k2_, genome_.nodes, state.input_idx, state.output_idx,
allow_input_keys=False, allow_output_keys=True)
conn_pos = fetch_first((genome_.conns[:, 0] == i_key) & (genome_.conns[:, 1] == o_key))
def nothing():
return genome_
def successful():
return genome_.add_conn(i_key, o_key, True, gene.new_conn_attrs(state))
def already_exist():
return genome_.update_conns(genome_.conns.at[conn_pos, 2].set(True))
is_already_exist = conn_pos != I_INT
if config.network_type == 'feedforward':
u_cons = unflatten_conns(genome_.nodes, genome_.conns)
cons_exist = jnp.where(~jnp.isnan(u_cons[0, :, :]), True, False)
is_cycle = check_cycles(genome_.nodes, cons_exist, from_idx, to_idx)
choice = jnp.where(is_already_exist, 0, jnp.where(is_cycle, 1, 2))
return jax.lax.switch(choice, [already_exist, nothing, successful])
elif config.network_type == 'recurrent':
return jax.lax.cond(is_already_exist, already_exist, successful)
else:
raise ValueError(f"Invalid network type: {config.network_type}")
def mutate_delete_conn(key_, genome_: Genome):
# randomly choose a connection
i_key, o_key, idx = choice_connection_key(key_, genome_.conns)
def nothing():
return genome_
def successfully_delete_connection():
return genome_.delete_conn_by_pos(idx)
return jax.lax.cond(idx == I_INT, nothing, successfully_delete_connection)
k1, k2, k3, k4 = jax.random.split(randkey, num=4)
r1, r2, r3, r4 = jax.random.uniform(k1, shape=(4,))
def no(k, g):
return g
genome = jax.lax.cond(r1 < config.node_add, mutate_add_node, no, k1, genome)
genome = jax.lax.cond(r2 < config.node_delete, mutate_delete_node, no, k2, genome)
genome = jax.lax.cond(r3 < config.conn_add, mutate_add_conn, no, k3, genome)
genome = jax.lax.cond(r4 < config.conn_delete, mutate_delete_conn, no, k4, genome)
return genome
def mutate_values(gene: Gene, state: State, randkey, genome: Genome):
k1, k2 = jax.random.split(randkey, num=2)
nodes_keys = jax.random.split(k1, num=genome.nodes.shape[0])
conns_keys = jax.random.split(k2, num=genome.conns.shape[0])
nodes_attrs, conns_attrs = genome.nodes[:, 1:], genome.conns[:, 3:]
new_nodes_attrs = vmap(gene.mutate_node, in_axes=(None, 0, 0))(state, nodes_keys, nodes_attrs)
new_conns_attrs = vmap(gene.mutate_conn, in_axes=(None, 0, 0))(state, conns_keys, conns_attrs)
# nan nodes not changed
new_nodes_attrs = jnp.where(jnp.isnan(nodes_attrs), jnp.nan, new_nodes_attrs)
new_conns_attrs = jnp.where(jnp.isnan(conns_attrs), jnp.nan, new_conns_attrs)
new_nodes = genome.nodes.at[:, 1:].set(new_nodes_attrs)
new_conns = genome.conns.at[:, 3:].set(new_conns_attrs)
return genome.update(new_nodes, new_conns)
def choice_node_key(rand_key: Array, nodes: Array,
input_keys: Array, output_keys: Array,
allow_input_keys: bool = False, allow_output_keys: bool = False) -> Tuple[Array, Array]:
"""
Randomly choose a node key from the given nodes. It guarantees that the chosen node not be the input or output node.
:param rand_key:
:param nodes:
:param input_keys:
:param output_keys:
:param allow_input_keys:
:param allow_output_keys:
:return: return its key and position(idx)
"""
node_keys = nodes[:, 0]
mask = ~jnp.isnan(node_keys)
if not allow_input_keys:
mask = jnp.logical_and(mask, ~jnp.isin(node_keys, input_keys))
if not allow_output_keys:
mask = jnp.logical_and(mask, ~jnp.isin(node_keys, output_keys))
idx = fetch_random(rand_key, mask)
key = jnp.where(idx != I_INT, nodes[idx, 0], jnp.nan)
return key, idx
def choice_connection_key(rand_key: Array, conns: Array):
"""
Randomly choose a connection key from the given connections.
:return: i_key, o_key, idx
"""
idx = fetch_random(rand_key, ~jnp.isnan(conns[:, 0]))
i_key = jnp.where(idx != I_INT, conns[idx, 0], jnp.nan)
o_key = jnp.where(idx != I_INT, conns[idx, 1], jnp.nan)
return i_key, o_key, idx