added inital scaler

This commit is contained in:
Kashif Rasul
2019-11-17 11:03:26 +01:00
parent 281874fcc2
commit aa9aa2ed81
3 changed files with 313 additions and 1 deletions
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from .distribution_output import ArgProj, Output, DistributionOutput, StudentTOutput
from .lambda_layer import LambdaLayer
from .feature import FeatureEmbedder, FeatureAssembler
from .feature import FeatureEmbedder, FeatureAssembler
from .scaler import MeanScaler, NOPScaler
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from typing import Tuple
from abc import ABC, abstractmethod
import torch
import torch.nn as nn
class Scaler(ABC, nn.Module):
def __init__(self, keepdim: bool = False):
super().__init__()
self.keepdim = keepdim
@abstractmethod
def compute_scale(
self, data: torch.Tensor, observed_indicator: torch.Tensor
) -> torch.Tensor:
pass
def forward(
self, data: torch.Tensor, observed_indicator: torch.Tensor
) -> Tuple[torch.Tensor, torch.Tensor]:
"""
Parameters
----------
data
tensor of shape (N, T, C) containing the data to be scaled
observed_indicator
observed_indicator: binary tensor with the same shape as
``data``, that has 1 in correspondence of observed data points,
and 0 in correspondence of missing data points.
Returns
-------
Tensor
Tensor containing the "scaled" data, shape: (N, T, C).
Tensor
Tensor containing the scale, of shape (N, C) if ``keepdim == False``, and shape
(N, 1, C) if ``keepdim == True``.
"""
scale = self.compute_scale(data, observed_indicator)
if self.keepdim:
scale = scale.unsqueeze(1)
return data / scale, scale
else:
return data / scale.unsqueeze(1), scale
class MeanScaler(Scaler):
"""
The ``MeanScaler`` computes a per-item scale according to the average
absolute value over time of each item. The average is computed only among
the observed values in the data tensor, as indicated by the second
argument. Items with no observed data are assigned a scale based on the
global average.
Parameters
----------
minimum_scale
default scale that is used if the time series has only zeros.
"""
def __init__(self, minimum_scale: float = 1e-10, *args, **kwargs):
super().__init__(*args, **kwargs)
self.minimum_scale = minimum_scale
def compute_scale(
self, data: torch.Tensor, observed_indicator: torch.Tensor
) -> torch.Tensor:
# these will have shape (N, C)
num_observed = observed_indicator.sum(dim=1)
sum_observed = (data.abs() * observed_indicator).sum(dim=1)
# first compute a global scale per-dimension
total_observed = num_observed.sum(dim=0)
denominator = torch.max(total_observed, torch.tensor(1.0))
default_scale = sum_observed.sum(dim=0) / denominator
# then compute a per-item, per-dimension scale
denominator = torch.max(num_observed, torch.tensor(1.0))
scale = sum_observed / denominator
# use per-batch scale when no element is observed
# or when the sequence contains only zeros
scale = torch.where(
sum_observed > torch.zeros_like(sum_observed),
scale,
default_scale * torch.ones_like(num_observed),
)
return torch.max(scale, torch.tensor(self.minimum_scale))
class NOPScaler(Scaler):
"""
The ``NOPScaler`` assigns a scale equals to 1 to each input item, i.e.,
no scaling is applied upon calling the ``NOPScaler``.
"""
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def compute_scale(
self, data: torch.Tensor, observed_indicator: torch.Tensor
) -> torch.Tensor:
return torch.ones_like(data).mean(dim=1)
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# Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License").
# You may not use this file except in compliance with the License.
# A copy of the License is located at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# or in the "license" file accompanying this file. This file 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 pytest
import numpy as np
import torch
from pts.modules import MeanScaler, NOPScaler
test_cases = [
(
MeanScaler(),
torch.tensor(
[
[1.0] * 50,
[0.0] * 25 + [3.0] * 25,
[2.0] * 49 + [1.5] * 1,
[0.0] * 50,
[1.0] * 50,
]
),
torch.tensor(
[
[1.0] * 50,
[0.0] * 25 + [1.0] * 25,
[0.0] * 49 + [1.0] * 1,
[1.0] * 50,
[0.0] * 50,
]
),
torch.tensor([1.0, 3.0, 1.5, 1.00396824, 1.00396824]),
),
(
MeanScaler(keepdim=True),
torch.tensor(
[
[1.0] * 50,
[0.0] * 25 + [3.0] * 25,
[2.0] * 49 + [1.5] * 1,
[0.0] * 50,
[1.0] * 50,
]
),
torch.tensor(
[
[1.0] * 50,
[0.0] * 25 + [1.0] * 25,
[0.0] * 49 + [1.0] * 1,
[1.0] * 50,
[0.0] * 50,
]
),
torch.tensor([1.0, 3.0, 1.5, 1.00396824, 1.00396824]).unsqueeze(1),
),
(
MeanScaler(),
torch.tensor(
[
[[1.0]] * 50,
[[0.0]] * 25 + [[3.0]] * 25,
[[2.0]] * 49 + [[1.5]] * 1,
[[0.0]] * 50,
[[1.0]] * 50,
]
),
torch.tensor(
[
[[1.0]] * 50,
[[0.0]] * 25 + [[1.0]] * 25,
[[0.0]] * 49 + [[1.0]] * 1,
[[1.0]] * 50,
[[0.0]] * 50,
]
),
torch.tensor([1.0, 3.0, 1.5, 1.00396824, 1.00396824]).unsqueeze(1),
),
(
MeanScaler(minimum_scale=1e-8),
torch.tensor(
[
[[1.0, 2.0]] * 50,
[[0.0, 0.0]] * 25 + [[3.0, 6.0]] * 25,
[[2.0, 4.0]] * 49 + [[1.5, 3.0]] * 1,
[[0.0, 0.0]] * 50,
[[1.0, 2.0]] * 50,
]
),
torch.tensor(
[
[[1.0, 1.0]] * 50,
[[0.0, 1.0]] * 25 + [[1.0, 0.0]] * 25,
[[1.0, 0.0]] * 49 + [[0.0, 1.0]] * 1,
[[1.0, 0.0]] * 50,
[[0.0, 1.0]] * 50,
]
),
torch.tensor(
[
[1.0, 2.0],
[3.0, 1.61111116],
[2.0, 3.0],
[1.28160918, 1.61111116],
[1.28160918, 2.0],
]
),
),
(
MeanScaler(),
torch.tensor(
[
[120.0] * 25 + [150.0] * 25,
[0.0] * 10 + [3.0] * 20 + [61.0] * 20,
[0.0] * 50,
[2e-2] * 10 + [0.0] * 30 + [3e-2] * 10,
]
),
torch.tensor(
[
[1.0] * 25 + [1.0] * 25,
[0.0] * 10 + [1.0] * 20 + [1.0] * 20,
[0.0] * 50,
[1.0] * 10 + [0.0] * 30 + [1.0] * 10,
]
),
torch.tensor([135.0, 32.0, 73.00454712, 2.5e-2]),
),
(
MeanScaler(),
torch.randn((5, 30)),
torch.zeros((5, 30)),
1e-10 * torch.ones((5,)),
),
(
MeanScaler(minimum_scale=1e-6),
torch.randn((5, 30, 1)),
torch.zeros((5, 30, 1)),
1e-6 * torch.ones((5, 1)),
),
(
MeanScaler(minimum_scale=1e-12),
torch.randn((5, 30, 3)),
torch.zeros((5, 30, 3)),
1e-12 * torch.ones((5, 3)),
),
(
NOPScaler(),
torch.randn((10, 20, 30)),
torch.randn((10, 20, 30)) > 0,
torch.ones((10, 30)),
),
(
NOPScaler(),
torch.randn((10, 20, 30)),
torch.ones((10, 20, 30)),
torch.ones((10, 30)),
),
(
NOPScaler(),
torch.randn((10, 20, 30)),
torch.zeros((10, 20, 30)),
torch.ones((10, 30)),
),
]
@pytest.mark.parametrize("s, target, observed, expected_scale", test_cases)
def test_scaler(s, target, observed, expected_scale):
target_scaled, scale = s(target, observed)
assert np.allclose(
expected_scale.numpy(), scale.numpy()
), "mismatch in the scale computation"
if s.keepdim:
expected_target_scaled = target / expected_scale
else:
expected_target_scaled = target / expected_scale.unsqueeze(1)
assert np.allclose(
expected_target_scaled.numpy(), target_scaled.numpy()
), "mismatch in the scaled target computation"
@pytest.mark.parametrize("target, observed", [])
def test_nopscaler(target, observed):
s = NOPScaler()
target_scaled, scale = s(target, observed)
assert torch.norm(target - target_scaled) == 0
assert torch.norm(torch.ones_like(target).mean(dim=1) - scale) == 0