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tensorneat-mend/tensorneat/algorithm/neat/neat.py
wls2002 18c3d44c79 complete fully stateful!
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2024-05-26 18:08:43 +08:00

112 lines
3.4 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,
):
self.species = species
self.genome = species.genome
def setup(self, state=State()):
state = self.species.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 self.species.ask(state)
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, fitness)
state = self.create_next_generation(state, winner, loser, elite_mask)
state = self.species.speciate(state)
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_randkeys = jax.random.split(k1, pop_size)
mutate_randkeys = jax.random.split(k2, pop_size)
wpn, wpc = state.pop_nodes[winner], state.pop_conns[winner]
lpn, lpc = state.pop_nodes[loser], state.pop_conns[loser]
# batch crossover
n_nodes, n_conns = jax.vmap(
self.genome.execute_crossover, in_axes=(None, 0, 0, 0, 0, 0)
)(
state, crossover_randkeys, wpn, wpc, lpn, lpc
) # new_nodes, new_conns
# batch mutation
m_n_nodes, m_n_conns = jax.vmap(
self.genome.execute_mutation, in_axes=(None, 0, 0, 0, 0)
)(
state, mutate_randkeys, n_nodes, n_conns, new_node_keys
) # mutated_new_nodes, mutated_new_conns
# 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.member_count
def generation(self, state: State):
# to analysis the algorithm
return state.generation