timm/models/layers/helpers.py

""" Layer/Module Helpers

Hacked together by / Copyright 2020 Ross Wightman
"""
from itertools import repeat
import collections.abc


# From PyTorch internals
def _ntuple(n):
    def parse(x):
        if isinstance(x, collections.abc.Iterable):
            return x
        return tuple(repeat(x, n))
    return parse


to_1tuple = _ntuple(1)
to_2tuple = _ntuple(2)
to_3tuple = _ntuple(3)
to_4tuple = _ntuple(4)
to_ntuple = _ntuple


def make_divisible(v, divisor=8, min_value=None, round_limit=.9):
    min_value = min_value or divisor
    new_v = max(min_value, int(v + divisor / 2) // divisor * divisor)
    # Make sure that round down does not go down by more than 10%.
    if new_v < round_limit * v:
        new_v += divisor
    return new_v