Files
tensorneat-mend/tensorneat/algorithm/neat/neat.py
wls2002 cf69b916af use black format all files;
remove "return state" for functions which will be executed in vmap;
recover randkey as args in mutation methods
2024-05-26 15:46:04 +08:00

116 lines
3.7 KiB
Python

import jax, jax.numpy as jnp
from utils import State
from .. import BaseAlgorithm
from .species import *
from .ga import *
from .genome import *
class NEAT(BaseAlgorithm):
def __init__(
self,
species: BaseSpecies,
mutation: BaseMutation = DefaultMutation(),
crossover: BaseCrossover = DefaultCrossover(),
):
self.genome: BaseGenome = species.genome
self.species = species
self.mutation = mutation
self.crossover = crossover
def setup(self, state=State()):
state = self.species.setup(state)
state = self.mutation.setup(state)
state = self.crossover.setup(state)
state = state.register(
generation=jnp.array(0.0),
next_node_key=jnp.array(
max(*self.genome.input_idx, *self.genome.output_idx) + 2,
dtype=jnp.float32,
),
)
return state
def ask(self, state: State):
return state, self.species.ask(state.species)
def tell(self, state: State, fitness):
k1, k2, randkey = jax.random.split(state.randkey, 3)
state = state.update(generation=state.generation + 1, randkey=randkey)
state, winner, loser, elite_mask = self.species.update_species(
state.species, fitness
)
state = self.create_next_generation(state, winner, loser, elite_mask)
state = self.species.speciate(state.species)
return state
def transform(self, state, individual):
"""transform the genome into a neural network"""
nodes, conns = individual
return self.genome.transform(state, nodes, conns)
def forward(self, state, inputs, transformed):
return self.genome.forward(state, inputs, transformed)
@property
def num_inputs(self):
return self.genome.num_inputs
@property
def num_outputs(self):
return self.genome.num_outputs
@property
def pop_size(self):
return self.species.pop_size
def create_next_generation(self, state, winner, loser, elite_mask):
# prepare random keys
pop_size = self.species.pop_size
new_node_keys = jnp.arange(pop_size) + state.next_node_key
k1, k2, randkey = jax.random.split(state.randkey, 3)
crossover_rand_keys = jax.random.split(k1, pop_size)
mutate_rand_keys = jax.random.split(k2, pop_size)
wpn, wpc = state.species.pop_nodes[winner], state.species.pop_conns[winner]
lpn, lpc = state.species.pop_nodes[loser], state.species.pop_conns[loser]
# batch crossover
n_nodes, n_conns = jax.vmap(self.crossover, in_axes=(0, None, 0, 0, 0, 0))(
crossover_rand_keys, self.genome, wpn, wpc, lpn, lpc
)
# batch mutation
m_n_nodes, m_n_conns = jax.vmap(self.mutation, in_axes=(0, None, 0, 0, 0))(
mutate_rand_keys, self.genome, n_nodes, n_conns, new_node_keys
)
# elitism don't mutate
pop_nodes = jnp.where(elite_mask[:, None, None], n_nodes, m_n_nodes)
pop_conns = jnp.where(elite_mask[:, None, None], n_conns, m_n_conns)
# update next node key
all_nodes_keys = pop_nodes[:, :, 0]
max_node_key = jnp.max(
jnp.where(jnp.isnan(all_nodes_keys), -jnp.inf, all_nodes_keys)
)
next_node_key = max_node_key + 1
return state.update(
randkey=randkey,
pop_nodes=pop_nodes,
pop_conns=pop_conns,
next_node_key=next_node_key,
)
def member_count(self, state: State):
return state, state.species.member_count
def generation(self, state: State):
# to analysis the algorithm
return state, state.generation