2020-01-17 12:30:26 +08:00

61 lines
2.1 KiB
Python

import numpy as np
class Dataset(object):
def __init__(self, data_map, deterministic=False, shuffle=True):
self.data_map = data_map
self.deterministic = deterministic
self.enable_shuffle = shuffle
self.n = next(iter(data_map.values())).shape[0]
self._next_id = 0
self.shuffle()
def shuffle(self):
if self.deterministic:
return
perm = np.arange(self.n)
np.random.shuffle(perm)
for key in self.data_map:
self.data_map[key] = self.data_map[key][perm]
self._next_id = 0
def next_batch(self, batch_size):
if self._next_id >= self.n and self.enable_shuffle:
self.shuffle()
cur_id = self._next_id
cur_batch_size = min(batch_size, self.n - self._next_id)
self._next_id += cur_batch_size
data_map = dict()
for key in self.data_map:
data_map[key] = self.data_map[key][cur_id:cur_id+cur_batch_size]
return data_map
def iterate_once(self, batch_size):
if self.enable_shuffle: self.shuffle()
while self._next_id <= self.n - batch_size:
yield self.next_batch(batch_size)
self._next_id = 0
def subset(self, num_elements, deterministic=True):
data_map = dict()
for key in self.data_map:
data_map[key] = self.data_map[key][:num_elements]
return Dataset(data_map, deterministic)
def iterbatches(arrays, *, num_batches=None, batch_size=None, shuffle=True, include_final_partial_batch=True):
assert (num_batches is None) != (batch_size is None), 'Provide num_batches or batch_size, but not both'
arrays = tuple(map(np.asarray, arrays))
n = arrays[0].shape[0]
assert all(a.shape[0] == n for a in arrays[1:])
inds = np.arange(n)
if shuffle: np.random.shuffle(inds)
sections = np.arange(0, n, batch_size)[1:] if num_batches is None else num_batches
for batch_inds in np.array_split(inds, sections):
if include_final_partial_batch or len(batch_inds) == batch_size:
yield tuple(a[batch_inds] for a in arrays)