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authorzhaohu xing <920232796@qq.com>2022-11-30 14:56:12 +0800
committerzhaohu xing <920232796@qq.com>2022-11-30 14:56:12 +0800
commit52cc83d36b7663a77b79fd2258d2ca871af73e55 (patch)
tree5c31e75a3934327331d5636bd6ef1420c3ba32fe /ldm/modules/distributions
parenta39a57cb1f5964d9af2b541f7b352576adeeac0f (diff)
fix bugs
Signed-off-by: zhaohu xing <920232796@qq.com>
Diffstat (limited to 'ldm/modules/distributions')
-rw-r--r--ldm/modules/distributions/__init__.py0
-rw-r--r--ldm/modules/distributions/distributions.py92
2 files changed, 0 insertions, 92 deletions
diff --git a/ldm/modules/distributions/__init__.py b/ldm/modules/distributions/__init__.py
deleted file mode 100644
index e69de29b..00000000
--- a/ldm/modules/distributions/__init__.py
+++ /dev/null
diff --git a/ldm/modules/distributions/distributions.py b/ldm/modules/distributions/distributions.py
deleted file mode 100644
index f2b8ef90..00000000
--- a/ldm/modules/distributions/distributions.py
+++ /dev/null
@@ -1,92 +0,0 @@
-import torch
-import numpy as np
-
-
-class AbstractDistribution:
- def sample(self):
- raise NotImplementedError()
-
- def mode(self):
- raise NotImplementedError()
-
-
-class DiracDistribution(AbstractDistribution):
- def __init__(self, value):
- self.value = value
-
- def sample(self):
- return self.value
-
- def mode(self):
- return self.value
-
-
-class DiagonalGaussianDistribution(object):
- def __init__(self, parameters, deterministic=False):
- self.parameters = parameters
- self.mean, self.logvar = torch.chunk(parameters, 2, dim=1)
- self.logvar = torch.clamp(self.logvar, -30.0, 20.0)
- self.deterministic = deterministic
- self.std = torch.exp(0.5 * self.logvar)
- self.var = torch.exp(self.logvar)
- if self.deterministic:
- self.var = self.std = torch.zeros_like(self.mean).to(device=self.parameters.device)
-
- def sample(self):
- x = self.mean + self.std * torch.randn(self.mean.shape).to(device=self.parameters.device)
- return x
-
- def kl(self, other=None):
- if self.deterministic:
- return torch.Tensor([0.])
- else:
- if other is None:
- return 0.5 * torch.sum(torch.pow(self.mean, 2)
- + self.var - 1.0 - self.logvar,
- dim=[1, 2, 3])
- else:
- return 0.5 * torch.sum(
- torch.pow(self.mean - other.mean, 2) / other.var
- + self.var / other.var - 1.0 - self.logvar + other.logvar,
- dim=[1, 2, 3])
-
- def nll(self, sample, dims=[1,2,3]):
- if self.deterministic:
- return torch.Tensor([0.])
- logtwopi = np.log(2.0 * np.pi)
- return 0.5 * torch.sum(
- logtwopi + self.logvar + torch.pow(sample - self.mean, 2) / self.var,
- dim=dims)
-
- def mode(self):
- return self.mean
-
-
-def normal_kl(mean1, logvar1, mean2, logvar2):
- """
- source: https://github.com/openai/guided-diffusion/blob/27c20a8fab9cb472df5d6bdd6c8d11c8f430b924/guided_diffusion/losses.py#L12
- Compute the KL divergence between two gaussians.
- Shapes are automatically broadcasted, so batches can be compared to
- scalars, among other use cases.
- """
- tensor = None
- for obj in (mean1, logvar1, mean2, logvar2):
- if isinstance(obj, torch.Tensor):
- tensor = obj
- break
- assert tensor is not None, "at least one argument must be a Tensor"
-
- # Force variances to be Tensors. Broadcasting helps convert scalars to
- # Tensors, but it does not work for torch.exp().
- logvar1, logvar2 = [
- x if isinstance(x, torch.Tensor) else torch.tensor(x).to(tensor)
- for x in (logvar1, logvar2)
- ]
-
- return 0.5 * (
- -1.0
- + logvar2
- - logvar1
- + torch.exp(logvar1 - logvar2)
- + ((mean1 - mean2) ** 2) * torch.exp(-logvar2)
- )