diffusers/tests/test_layers_utils.py

116 lines
4.1 KiB
Python
Executable File

# coding=utf-8
# Copyright 2022 HuggingFace Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import inspect
import tempfile
import unittest
import numpy as np
import torch
from diffusers.models.embeddings import get_timestep_embedding
from diffusers.testing_utils import floats_tensor, slow, torch_device
torch.backends.cuda.matmul.allow_tf32 = False
class EmbeddingsTests(unittest.TestCase):
def test_timestep_embeddings(self):
embedding_dim = 256
timesteps = torch.arange(16)
t1 = get_timestep_embedding(timesteps, embedding_dim)
# first vector should always be composed only of 0's and 1's
assert (t1[0, : embedding_dim // 2] - 0).abs().sum() < 1e-5
assert (t1[0, embedding_dim // 2 :] - 1).abs().sum() < 1e-5
# last element of each vector should be one
assert (t1[:, -1] - 1).abs().sum() < 1e-5
# For large embeddings (e.g. 128) the frequency of every vector is higher
# than the previous one which means that the gradients of later vectors are
# ALWAYS higher than the previous ones
grad_mean = np.abs(np.gradient(t1, axis=-1)).mean(axis=1)
prev_grad = 0.0
for grad in grad_mean:
assert grad > prev_grad
prev_grad = grad
def test_timestep_defaults(self):
embedding_dim = 16
timesteps = torch.arange(10)
t1 = get_timestep_embedding(timesteps, embedding_dim)
t2 = get_timestep_embedding(
timesteps, embedding_dim, flip_sin_to_cos=False, downscale_freq_shift=1, max_period=10_000
)
assert torch.allclose(t1.cpu(), t2.cpu(), 1e-3)
def test_timestep_flip_sin_cos(self):
embedding_dim = 16
timesteps = torch.arange(10)
t1 = get_timestep_embedding(timesteps, embedding_dim, flip_sin_to_cos=True)
t1 = torch.cat([t1[:, embedding_dim // 2 :], t1[:, : embedding_dim // 2]], dim=-1)
t2 = get_timestep_embedding(timesteps, embedding_dim, flip_sin_to_cos=False)
assert torch.allclose(t1.cpu(), t2.cpu(), 1e-3)
def test_timestep_downscale_freq_shift(self):
embedding_dim = 16
timesteps = torch.arange(10)
t1 = get_timestep_embedding(timesteps, embedding_dim, downscale_freq_shift=0)
t2 = get_timestep_embedding(timesteps, embedding_dim, downscale_freq_shift=1)
# get cosine half (vectors that are wrapped into cosine)
cosine_half = (t1 - t2)[:, embedding_dim // 2 :]
# cosine needs to be negative
assert (np.abs((cosine_half <= 0).numpy()) - 1).sum() < 1e-5
def test_sinoid_embeddings_hardcoded(self):
embedding_dim = 64
timesteps = torch.arange(128)
# standard unet, score_vde
t1 = get_timestep_embedding(timesteps, embedding_dim, downscale_freq_shift=1, flip_sin_to_cos=False)
# glide, ldm
t2 = get_timestep_embedding(timesteps, embedding_dim, downscale_freq_shift=0, flip_sin_to_cos=True)
# grad-tts
t3 = get_timestep_embedding(timesteps, embedding_dim, scale=1000)
assert torch.allclose(
t1[23:26, 47:50].flatten().cpu(),
torch.tensor([0.9646, 0.9804, 0.9892, 0.9615, 0.9787, 0.9882, 0.9582, 0.9769, 0.9872]),
1e-3,
)
assert torch.allclose(
t2[23:26, 47:50].flatten().cpu(),
torch.tensor([0.3019, 0.2280, 0.1716, 0.3146, 0.2377, 0.1790, 0.3272, 0.2474, 0.1864]),
1e-3,
)
assert torch.allclose(
t3[23:26, 47:50].flatten().cpu(),
torch.tensor([-0.9801, -0.9464, -0.9349, -0.3952, 0.8887, -0.9709, 0.5299, -0.2853, -0.9927]),
1e-3,
)