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

141 lines
4.5 KiB
Python

from functools import partial
from typing import Tuple
import jax
from jax import numpy as jnp, Array
from jax import jit
I_INT = jnp.iinfo(jnp.int32).max # infinite int
EMPTY_NODE = jnp.full((1, 5), jnp.nan)
EMPTY_CON = jnp.full((1, 4), jnp.nan)
@jit
def flatten_connections(keys, connections):
"""
flatten the (2, N, N) connections to (N * N, 4)
:param keys:
:param connections:
:return:
the first two columns are the index of the node
the 3rd column is the weight, and the 4th column is the enabled status
"""
indices_x, indices_y = jnp.meshgrid(keys, keys, indexing='ij')
indices = jnp.stack((indices_x, indices_y), axis=-1).reshape(-1, 2)
# make (2, N, N) to (N, N, 2)
con = jnp.transpose(connections, (1, 2, 0))
# make (N, N, 2) to (N * N, 2)
con = jnp.reshape(con, (-1, 2))
con = jnp.concatenate((indices, con), axis=1)
return con
@partial(jit, static_argnames=['N'])
def unflatten_connections(N, cons):
"""
restore the (N * N, 4) connections to (2, N, N)
:param N:
:param cons:
:return:
"""
cons = cons[:, 2:] # remove the indices
unflatten_cons = jnp.moveaxis(cons.reshape(N, N, 2), -1, 0)
return unflatten_cons
@jit
def set_operation_analysis(ar1: Array, ar2: Array) -> Tuple[Array, Array, Array]:
"""
Analyze the intersection and union of two arrays by returning their sorted concatenation indices,
intersection mask, and union mask.
:param ar1: JAX array of shape (N, M)
First input array. Should have the same shape as ar2.
:param ar2: JAX array of shape (N, M)
Second input array. Should have the same shape as ar1.
:return: tuple of 3 arrays
- sorted_indices: Indices that would sort the concatenation of ar1 and ar2.
- intersect_mask: A boolean array indicating the positions of the common elements between ar1 and ar2
in the sorted concatenation.
- union_mask: A boolean array indicating the positions of the unique elements in the union of ar1 and ar2
in the sorted concatenation.
Examples:
a = jnp.array([[1, 2], [3, 4], [5, 6]])
b = jnp.array([[1, 2], [7, 8], [9, 10]])
sorted_indices, intersect_mask, union_mask = set_operation_analysis(a, b)
sorted_indices -> array([0, 1, 2, 3, 4, 5])
intersect_mask -> array([True, False, False, False, False, False])
union_mask -> array([False, True, True, True, True, True])
"""
ar = jnp.concatenate((ar1, ar2), axis=0)
sorted_indices = jnp.lexsort(ar.T[::-1])
aux = ar[sorted_indices]
aux = jnp.concatenate((aux, jnp.full((1, ar1.shape[1]), jnp.nan)), axis=0)
nan_mask = jnp.any(jnp.isnan(aux), axis=1)
fr, sr = aux[:-1], aux[1:] # first row, second row
intersect_mask = jnp.all(fr == sr, axis=1) & ~nan_mask[:-1]
union_mask = jnp.any(fr != sr, axis=1) & ~nan_mask[:-1]
return sorted_indices, intersect_mask, union_mask
@jit
def fetch_first(mask, default=I_INT) -> Array:
"""
fetch the first True index
:param mask: array of bool
:param default: the default value if no element satisfying the condition
:return: the index of the first element satisfying the condition. if no element satisfying the condition, return I_INT
example:
>>> a = jnp.array([1, 2, 3, 4, 5])
>>> fetch_first(a > 3)
3
>>> fetch_first(a > 30)
I_INT
"""
idx = jnp.argmax(mask)
return jnp.where(mask[idx], idx, default)
@jit
def fetch_last(mask, default=I_INT) -> Array:
"""
similar to fetch_first, but fetch the last True index
"""
reversed_idx = fetch_first(mask[::-1], default)
return jnp.where(reversed_idx == -1, -1, mask.shape[0] - reversed_idx - 1)
@jit
def fetch_random(rand_key, mask, default=I_INT) -> Array:
"""
similar to fetch_first, but fetch a random True index
"""
true_cnt = jnp.sum(mask)
cumsum = jnp.cumsum(mask)
target = jax.random.randint(rand_key, shape=(), minval=1, maxval=true_cnt + 1)
mask = jnp.where(true_cnt == 0, False, cumsum >= target)
return fetch_first(mask, default)
if __name__ == '__main__':
a = jnp.array([1, 2, 3, 4, 5])
print(fetch_first(a > 3))
print(fetch_first(a > 30))
print(fetch_last(a > 3))
print(fetch_last(a > 30))
rand_key = jax.random.PRNGKey(0)
for t in [-1, 0, 1, 2, 3, 4, 5]:
for _ in range(10):
rand_key, _ = jax.random.split(rand_key)
print(jax.random.randint(rand_key, shape=(), minval=1, maxval=2))
print(t, fetch_random(rand_key, a > t))