Upload 2 files
Browse files
app.py
CHANGED
@@ -727,4 +727,4 @@ with gr.Blocks(theme=gr.themes.Default()) as demo:
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if __name__ == "__main__":
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demo.queue()
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demo.launch(
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if __name__ == "__main__":
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demo.queue()
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demo.launch()
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vae.py
CHANGED
@@ -1,14 +1,20 @@
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import numpy as np
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import torch
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import torch.nn as nn
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import torch.nn.functional as F
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import torch.distributions as dist
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EPS = -9 # minimum logscale
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@torch.jit.script
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def gaussian_kl(
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return (
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-0.5
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+ p_logscale
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@@ -20,27 +26,27 @@ def gaussian_kl(q_loc, q_logscale, p_loc, p_logscale):
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@torch.jit.script
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def sample_gaussian(loc, logscale):
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return loc + logscale.exp() * torch.randn_like(loc)
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class Block(nn.Module):
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def __init__(
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self,
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in_width,
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bottleneck,
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out_width,
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kernel_size=3,
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residual=True,
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down_rate=None,
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version=None,
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):
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super().__init__()
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self.d = down_rate
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self.residual = residual
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padding = 0 if kernel_size == 1 else 1
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if version == "light": #
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activation = nn.ReLU()
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self.conv = nn.Sequential(
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activation,
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@@ -64,7 +70,7 @@ class Block(nn.Module):
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if self.residual and (self.d or in_width > out_width):
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self.width_proj = nn.Conv2d(in_width, out_width, 1, 1)
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def forward(self, x):
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out = self.conv(x)
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if self.residual:
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if x.shape[1] != out.shape[1]:
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@@ -79,7 +85,7 @@ class Block(nn.Module):
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class Encoder(nn.Module):
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def __init__(self, args):
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super().__init__()
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# parse architecture
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stages = []
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@@ -91,23 +97,17 @@ class Encoder(nn.Module):
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if i == 0: # define network stem
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if n_blocks == 0 and "d" not in stage:
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print("Using stride=2 conv encoder stem.")
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args.input_channels,
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args.widths[1],
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kernel_size=7,
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stride=2,
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padding=3,
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)
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continue
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else:
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stages += [(args.widths[i], None) for _ in range(n_blocks)]
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if "d" in stage: # downsampling block
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stages += [(args.widths[i + 1], int(stage[stage.index("d") + 1]))]
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blocks.append(
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Block(prev_width, bottleneck, width, down_rate=d, version=args.vr)
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)
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# scale weights of last conv layer in each block
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for b in blocks:
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b.conv[-1].weight.data *= np.sqrt(1 / len(blocks))
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self.blocks = nn.ModuleList(blocks)
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def forward(self, x):
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x = self.stem(x)
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acts = {}
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for block in self.blocks:
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class DecoderBlock(nn.Module):
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def __init__(self, args, in_width, out_width, resolution):
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super().__init__()
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bottleneck = int(in_width / args.bottleneck)
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self.res = resolution
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self.stochastic = self.res <= args.z_max_res
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self.z_dim = args.z_dim
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self.cond_prior = args.cond_prior
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k = 3 if self.res > 2 else 1
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if self.cond_prior: # conditional prior
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p_in_width = in_width + args.context_dim
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else: # exogenous prior
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p_in_width = in_width
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# self.z_feat_proj = nn.Conv2d(self.z_dim + in_width, out_width, 1)
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self.z_feat_proj = nn.Conv2d(self.z_dim + in_width, out_width, 1)
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self.prior = Block(
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bottleneck,
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2 * self.z_dim + in_width,
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kernel_size=k,
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version=args.vr,
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)
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self.z_proj = nn.Conv2d(self.z_dim + args.context_dim, in_width, 1)
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self.conv = Block(
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in_width, bottleneck, out_width, kernel_size=k, version=args.vr
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)
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def forward_prior(
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if self.cond_prior:
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z = torch.cat([z, pa], dim=1)
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z = self.prior(z)
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@@ -185,8 +188,18 @@ class DecoderBlock(nn.Module):
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p_logscale = p_logscale + torch.tensor(t).to(z.device).log()
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return p_loc, p_logscale, p_features
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def forward_posterior(
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h = torch.cat([z, pa, x], dim=1)
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q_loc, q_logscale = self.posterior(h).chunk(2, dim=1)
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if t is not None:
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q_logscale = q_logscale + torch.tensor(t).to(z.device).log()
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@@ -194,7 +207,7 @@ class DecoderBlock(nn.Module):
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class Decoder(nn.Module):
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def __init__(self, args):
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super().__init__()
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# parse architecture
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stages = []
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@@ -218,73 +231,58 @@ class Decoder(nn.Module):
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)
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self.bias = nn.ParameterList(bias)
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self.cond_prior = args.cond_prior
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self.is_drop_cond = True if "
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def
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# learnt params for each resolution r
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bias = {r.shape[2]: r for r in self.bias}
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h = bias[1].repeat(parents.shape[0], 1, 1, 1) #
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stats = []
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for i, block in enumerate(self.blocks):
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res = block.res # current block resolution, e.g. 64x64
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pa = parents[..., :res, :res].clone() # select parents @ res
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else: # for ukbb
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pa_drop1 = pa_drop2 = pa
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if h.size(-1) < res: # upsample previous layer output
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b = bias[res] if res in bias.keys() else 0 # broadcasting
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h = b + F.interpolate(h, scale_factor=res / h.shape[-1])
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if block.
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#
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p_loc, p_logscale, p_feat = block.forward_prior(z, t=t)
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# computation tree:
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# decoder block
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# / \
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# deterministic stochastic
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# | / \
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# forward z = p_loc given x not given x
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# / / \
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# abduct forward z or z* z ~ prior
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# / \ |
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# (prior: conditional exogenous) get p(z|pa*) if abduct
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# get z* get z
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#
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if block.stochastic:
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if x is not None: # z_i ~ q(z_i | z_<i,
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z = sample_gaussian(q_loc, q_logscale)
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stat = dict(kl=gaussian_kl(q_loc, q_logscale, p_loc, p_logscale))
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# abduct exogenous noise
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if abduct:
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if block.cond_prior: # z* if conditional prior
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stat.update(
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dict(
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)
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)
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else: # z if exogenous prior
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stat.update(dict(z=z)) # if cf training
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stats.append(stat)
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else:
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z = sample_gaussian(p_loc, p_logscale)
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if abduct and block.cond_prior: # for abducting z*
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stats.append(
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dict(z={"p_loc": p_loc, "p_logscale": p_logscale})
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)
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z = latents[i]
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except: # sample prior
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z = sample_gaussian(p_loc, p_logscale)
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if abduct and block.cond_prior: # for abducting z*
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stats.append(
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dict(z={"p_loc": p_loc, "p_logscale": p_logscale})
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)
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else:
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z = p_loc # deterministic path
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h = h + p_feat # merge prior features
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return h, stats
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def
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opt = dist.Categorical(1 / 3 * torch.ones(3)).sample()
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if opt == 0: # drop stochastic path
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elif opt == 1: # drop deterministic path
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elif opt == 2: # keep both
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return
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class DGaussNet(nn.Module):
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def __init__(self, args):
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super(DGaussNet, self).__init__()
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self.x_loc = nn.Conv2d(
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args.widths[0], args.input_channels, kernel_size=1, stride=1
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else:
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NotImplementedError(f"{args.x_like} not implemented.")
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def forward(
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loc, logscale = self.x_loc(h), self.x_logscale(h).clamp(min=EPS)
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# for RGB inputs
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if t is not None:
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logscale = logscale + torch.tensor(t).to(h.device).log()
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return loc, logscale
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def approx_cdf(self, x):
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return 0.5 * (
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1.0 + torch.tanh(np.sqrt(2.0 / np.pi) * (x + 0.044715 * torch.pow(x, 3)))
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)
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def nll(self, h, x):
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loc, logscale = self.forward(h, x)
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centered_x = x - loc
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inv_stdv = torch.exp(-logscale)
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)
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return -1.0 * log_probs.mean(dim=(1, 2, 3))
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def sample(
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if return_loc:
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x, logscale = self.forward(h)
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else:
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class HVAE(nn.Module):
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def __init__(self, args):
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super().__init__()
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args.vr = "light" if "ukbb" in args.hps else None # hacky
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self.encoder = Encoder(args)
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NotImplementedError(f"{args.x_like} not implemented.")
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self.cond_prior = args.cond_prior
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self.free_bits = args.kl_free_bits
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def forward(self, x, parents, beta=1):
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acts = self.encoder(x)
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h, stats = self.decoder(parents=parents, x=acts)
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nll_pp = self.likelihood.nll(h, x)
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if self.free_bits > 0:
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free_bits = torch.tensor(self.free_bits).type_as(nll_pp)
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).sum()
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else:
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kl_pp = torch.zeros_like(nll_pp)
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for
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kl_pp += stat["kl"].sum(dim=(1, 2, 3))
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kl_pp = kl_pp / np.prod(x.shape[1:]) # per pixel
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h, _ = self.decoder(parents=parents, t=t)
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return self.likelihood.sample(h, return_loc, t=t)
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def abduct(
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acts = self.encoder(x)
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_, q_stats = self.decoder(
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x=acts, parents=parents, abduct=True, t=t
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# Option1: mixture distribution: r(z_i | z_{<i}, x, pa, pa*)
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# = a*q(z_i | z_{<i}, x, pa) + (1-a)*p(z_i | z_{<i}, pa*)
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r_loc = alpha * q_loc + (1 - alpha) * p_loc
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# r_var = a*(q_loc.pow(2) + q_var) + (1-a)*(p_loc.pow(2) + p_var) - r_loc.pow(2)
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# # Option 2: precision weighted distribution
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else:
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return q_stats # zs
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def forward_latents(
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h, _ = self.decoder(latents=latents, parents=parents, t=t)
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return self.likelihood.sample(h, t=t)
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from typing import Dict, List, Optional, Tuple
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import numpy as np
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import torch
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import torch.distributions as dist
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import torch.nn.functional as F
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from torch import Tensor, nn
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from hps import Hparams
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EPS = -9 # minimum logscale
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@torch.jit.script
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def gaussian_kl(
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q_loc: Tensor, q_logscale: Tensor, p_loc: Tensor, p_logscale: Tensor
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) -> Tensor:
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return (
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-0.5
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+ p_logscale
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@torch.jit.script
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def sample_gaussian(loc: Tensor, logscale: Tensor) -> Tensor:
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return loc + logscale.exp() * torch.randn_like(loc)
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class Block(nn.Module):
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def __init__(
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self,
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in_width: int,
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bottleneck: int,
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out_width: int,
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kernel_size: int = 3,
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residual: bool = True,
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down_rate: Optional[int] = None,
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version: Optional[str] = None,
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):
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super().__init__()
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self.d = down_rate
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self.residual = residual
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padding = 0 if kernel_size == 1 else 1
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if version == "light": # uses less VRAM
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activation = nn.ReLU()
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self.conv = nn.Sequential(
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activation,
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if self.residual and (self.d or in_width > out_width):
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self.width_proj = nn.Conv2d(in_width, out_width, 1, 1)
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def forward(self, x: Tensor) -> Tensor:
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out = self.conv(x)
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if self.residual:
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if x.shape[1] != out.shape[1]:
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class Encoder(nn.Module):
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def __init__(self, args: Hparams):
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super().__init__()
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# parse architecture
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stages = []
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if i == 0: # define network stem
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if n_blocks == 0 and "d" not in stage:
|
99 |
print("Using stride=2 conv encoder stem.")
|
100 |
+
stem_width, stem_stride = args.widths[1], 2
|
|
|
|
|
|
|
|
|
|
|
|
|
101 |
continue
|
102 |
else:
|
103 |
+
stem_width, stem_stride = args.widths[0], 1
|
104 |
+
self.stem = nn.Conv2d(
|
105 |
+
args.input_channels,
|
106 |
+
stem_width,
|
107 |
+
kernel_size=7,
|
108 |
+
stride=stem_stride,
|
109 |
+
padding=3,
|
110 |
+
)
|
111 |
stages += [(args.widths[i], None) for _ in range(n_blocks)]
|
112 |
if "d" in stage: # downsampling block
|
113 |
stages += [(args.widths[i + 1], int(stage[stage.index("d") + 1]))]
|
|
|
118 |
blocks.append(
|
119 |
Block(prev_width, bottleneck, width, down_rate=d, version=args.vr)
|
120 |
)
|
|
|
121 |
for b in blocks:
|
122 |
b.conv[-1].weight.data *= np.sqrt(1 / len(blocks))
|
123 |
self.blocks = nn.ModuleList(blocks)
|
124 |
|
125 |
+
def forward(self, x: Tensor) -> Dict[int, Tensor]:
|
126 |
x = self.stem(x)
|
127 |
acts = {}
|
128 |
for block in self.blocks:
|
|
|
135 |
|
136 |
|
137 |
class DecoderBlock(nn.Module):
|
138 |
+
def __init__(self, args: Hparams, in_width: int, out_width: int, resolution: int):
|
139 |
super().__init__()
|
140 |
bottleneck = int(in_width / args.bottleneck)
|
141 |
self.res = resolution
|
142 |
self.stochastic = self.res <= args.z_max_res
|
143 |
self.z_dim = args.z_dim
|
144 |
self.cond_prior = args.cond_prior
|
145 |
+
self.q_correction = args.q_correction
|
146 |
k = 3 if self.res > 2 else 1
|
147 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
148 |
self.prior = Block(
|
149 |
+
(in_width + args.context_dim if self.cond_prior else in_width),
|
150 |
bottleneck,
|
151 |
2 * self.z_dim + in_width,
|
152 |
kernel_size=k,
|
|
|
163 |
version=args.vr,
|
164 |
)
|
165 |
self.z_proj = nn.Conv2d(self.z_dim + args.context_dim, in_width, 1)
|
166 |
+
if not self.q_correction: # for no posterior correction
|
167 |
+
self.z_feat_proj = nn.Conv2d(self.z_dim + in_width, out_width, 1)
|
168 |
self.conv = Block(
|
169 |
in_width, bottleneck, out_width, kernel_size=k, version=args.vr
|
170 |
)
|
171 |
|
172 |
+
def forward_prior(
|
173 |
+
self, z: Tensor, pa: Optional[Tensor] = None, t: Optional[float] = None
|
174 |
+
) -> Tuple[Tensor, Tensor, Tensor]:
|
175 |
+
#print('Prior')
|
176 |
+
#print('z')
|
177 |
+
#print(z.shape)
|
178 |
+
#print('pa')
|
179 |
+
#print(pa.shape)
|
180 |
+
|
181 |
if self.cond_prior:
|
182 |
z = torch.cat([z, pa], dim=1)
|
183 |
z = self.prior(z)
|
|
|
188 |
p_logscale = p_logscale + torch.tensor(t).to(z.device).log()
|
189 |
return p_loc, p_logscale, p_features
|
190 |
|
191 |
+
def forward_posterior(
|
192 |
+
self, z: Tensor, x: Tensor, pa: Tensor, t: Optional[float] = None
|
193 |
+
) -> Tuple[Tensor, Tensor]:
|
194 |
+
#print('Posterior')
|
195 |
+
#print('z')
|
196 |
+
#print(z.shape)
|
197 |
+
#print('x')
|
198 |
+
#print(x.shape)
|
199 |
+
#print('pa')
|
200 |
+
#print(pa.shape)
|
201 |
h = torch.cat([z, pa, x], dim=1)
|
202 |
+
#print('h shape: ', h.shape)
|
203 |
q_loc, q_logscale = self.posterior(h).chunk(2, dim=1)
|
204 |
if t is not None:
|
205 |
q_logscale = q_logscale + torch.tensor(t).to(z.device).log()
|
|
|
207 |
|
208 |
|
209 |
class Decoder(nn.Module):
|
210 |
+
def __init__(self, args: Hparams):
|
211 |
super().__init__()
|
212 |
# parse architecture
|
213 |
stages = []
|
|
|
231 |
)
|
232 |
self.bias = nn.ParameterList(bias)
|
233 |
self.cond_prior = args.cond_prior
|
234 |
+
self.is_drop_cond = True if "morphomnist" in args.hps else False # hacky
|
235 |
|
236 |
+
def forward(
|
237 |
+
self,
|
238 |
+
parents: Tensor,
|
239 |
+
x: Optional[Dict[int, Tensor]] = None,
|
240 |
+
t: Optional[float] = None,
|
241 |
+
abduct: bool = False,
|
242 |
+
latents: List[Tensor] = [],
|
243 |
+
) -> Tuple[Tensor, List[Dict[str, Tensor]]]:
|
244 |
# learnt params for each resolution r
|
245 |
bias = {r.shape[2]: r for r in self.bias}
|
246 |
+
h = z = bias[1].repeat(parents.shape[0], 1, 1, 1) # initial state
|
247 |
+
# conditioning dropout: stochastic path (p_sto), deterministic path (p_det)
|
248 |
+
p_sto, p_det = (
|
249 |
+
self.drop_cond() if (self.training and self.cond_prior) else (1, 1)
|
250 |
+
)
|
251 |
|
252 |
stats = []
|
253 |
for i, block in enumerate(self.blocks):
|
254 |
res = block.res # current block resolution, e.g. 64x64
|
255 |
pa = parents[..., :res, :res].clone() # select parents @ res
|
256 |
|
257 |
+
# for morphomnist w/ conditioning dropout of y only, clean up later
|
258 |
+
if self.is_drop_cond:
|
259 |
+
pa_sto, pa_det = pa.clone(), pa.clone()
|
260 |
+
pa_sto[:, 2:, ...] = pa_sto[:, 2:, ...] * p_sto
|
261 |
+
pa_det[:, 2:, ...] = pa_det[:, 2:, ...] * p_det
|
262 |
+
else: # disabled otherwise
|
263 |
+
pa_sto = pa_det = pa
|
|
|
|
|
264 |
|
265 |
if h.size(-1) < res: # upsample previous layer output
|
266 |
b = bias[res] if res in bias.keys() else 0 # broadcasting
|
267 |
h = b + F.interpolate(h, scale_factor=res / h.shape[-1])
|
268 |
|
269 |
+
if block.q_correction:
|
270 |
+
p_input = h # current prior depends on previous posterior
|
271 |
+
else: # current prior depends on previous prior only, upsample previous prior latent z
|
272 |
+
p_input = (
|
273 |
+
b + F.interpolate(z, scale_factor=res / z.shape[-1])
|
274 |
+
if z.size(-1) < res
|
275 |
+
else z
|
276 |
+
)
|
277 |
+
p_loc, p_logscale, p_feat = block.forward_prior(p_input, pa_sto, t=t)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
278 |
|
279 |
if block.stochastic:
|
280 |
+
if x is not None: # z_i ~ q(z_i | z_<i, x, pa_x)
|
281 |
+
# print(res)
|
282 |
+
q_loc, q_logscale = block.forward_posterior(h, x[res], pa, t=t)
|
283 |
z = sample_gaussian(q_loc, q_logscale)
|
284 |
stat = dict(kl=gaussian_kl(q_loc, q_logscale, p_loc, p_logscale))
|
285 |
+
if abduct: # abduct exogenous noise
|
|
|
286 |
if block.cond_prior: # z* if conditional prior
|
287 |
stat.update(
|
288 |
dict(
|
|
|
290 |
)
|
291 |
)
|
292 |
else: # z if exogenous prior
|
293 |
+
stat.update(dict(z=z)) # .detach() z if not cf training
|
|
|
294 |
stats.append(stat)
|
295 |
else:
|
296 |
+
try: # forward abducted latents
|
297 |
+
z = latents[i]
|
298 |
+
z = sample_gaussian(p_loc, p_logscale) if z is None else z
|
299 |
+
except: # sample prior
|
300 |
z = sample_gaussian(p_loc, p_logscale)
|
|
|
301 |
if abduct and block.cond_prior: # for abducting z*
|
302 |
stats.append(
|
303 |
dict(z={"p_loc": p_loc, "p_logscale": p_logscale})
|
304 |
)
|
305 |
+
else: # deterministic block
|
306 |
+
z = p_loc
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
307 |
h = h + p_feat # merge prior features
|
308 |
+
# h_i = h_<i + f(z_i, pa_x)
|
309 |
+
h = h + block.z_proj(torch.cat([z, pa], dim=1))
|
310 |
+
h = block.conv(h)
|
311 |
+
|
312 |
+
if not block.q_correction:
|
313 |
+
if (i + 1) < len(self.blocks):
|
314 |
+
# z independent of pa_x for next layer prior
|
315 |
+
z = block.z_feat_proj(torch.cat([z, p_feat], dim=1))
|
316 |
return h, stats
|
317 |
|
318 |
+
def _scale_weights(self):
|
319 |
+
scale = np.sqrt(1 / len(self.blocks))
|
320 |
+
for b in self.blocks:
|
321 |
+
b.z_proj.weight.data *= scale
|
322 |
+
b.conv.conv[-1].weight.data *= scale
|
323 |
+
b.prior.conv[-1].weight.data *= 0.0
|
324 |
|
325 |
+
@torch.no_grad()
|
326 |
+
def drop_cond(self) -> Tuple[int, int]:
|
327 |
opt = dist.Categorical(1 / 3 * torch.ones(3)).sample()
|
328 |
if opt == 0: # drop stochastic path
|
329 |
+
p_sto, p_det = 0, 1
|
330 |
elif opt == 1: # drop deterministic path
|
331 |
+
p_sto, p_det = 1, 0
|
332 |
elif opt == 2: # keep both
|
333 |
+
p_sto, p_det = 1, 1
|
334 |
+
return p_sto, p_det
|
335 |
|
336 |
|
337 |
class DGaussNet(nn.Module):
|
338 |
+
def __init__(self, args: Hparams):
|
339 |
super(DGaussNet, self).__init__()
|
340 |
self.x_loc = nn.Conv2d(
|
341 |
args.widths[0], args.input_channels, kernel_size=1, stride=1
|
|
|
364 |
else:
|
365 |
NotImplementedError(f"{args.x_like} not implemented.")
|
366 |
|
367 |
+
def forward(
|
368 |
+
self, h: Tensor, x: Optional[Tensor] = None, t: Optional[float] = None
|
369 |
+
) -> Tuple[Tensor, Tensor]:
|
370 |
loc, logscale = self.x_loc(h), self.x_logscale(h).clamp(min=EPS)
|
371 |
|
372 |
# for RGB inputs
|
373 |
+
if hasattr(self, "channel_coeffs"):
|
374 |
+
coeff = torch.tanh(self.channel_coeffs(h))
|
375 |
+
if x is None: # inference
|
376 |
+
# loc = loc + logscale.exp() * torch.randn_like(loc) # random sampling
|
377 |
+
f = lambda x: torch.clamp(x, min=-1, max=1)
|
378 |
+
loc_red = f(loc[:, 0, ...])
|
379 |
+
loc_green = f(loc[:, 1, ...] + coeff[:, 0, ...] * loc_red)
|
380 |
+
loc_blue = f(
|
381 |
+
loc[:, 2, ...]
|
382 |
+
+ coeff[:, 1, ...] * loc_red
|
383 |
+
+ coeff[:, 2, ...] * loc_green
|
384 |
+
)
|
385 |
+
else: # training
|
386 |
+
loc_red = loc[:, 0, ...]
|
387 |
+
loc_green = loc[:, 1, ...] + coeff[:, 0, ...] * x[:, 0, ...]
|
388 |
+
loc_blue = (
|
389 |
+
loc[:, 2, ...]
|
390 |
+
+ coeff[:, 1, ...] * x[:, 0, ...]
|
391 |
+
+ coeff[:, 2, ...] * x[:, 1, ...]
|
392 |
+
)
|
393 |
+
|
394 |
+
loc = torch.cat(
|
395 |
+
[loc_red.unsqueeze(1), loc_green.unsqueeze(1), loc_blue.unsqueeze(1)],
|
396 |
+
dim=1,
|
397 |
+
)
|
398 |
|
399 |
if t is not None:
|
400 |
logscale = logscale + torch.tensor(t).to(h.device).log()
|
401 |
return loc, logscale
|
402 |
|
403 |
+
def approx_cdf(self, x: Tensor) -> Tensor:
|
404 |
return 0.5 * (
|
405 |
1.0 + torch.tanh(np.sqrt(2.0 / np.pi) * (x + 0.044715 * torch.pow(x, 3)))
|
406 |
)
|
407 |
|
408 |
+
def nll(self, h: Tensor, x: Tensor) -> Tensor:
|
409 |
loc, logscale = self.forward(h, x)
|
410 |
centered_x = x - loc
|
411 |
inv_stdv = torch.exp(-logscale)
|
|
|
425 |
)
|
426 |
return -1.0 * log_probs.mean(dim=(1, 2, 3))
|
427 |
|
428 |
+
def sample(
|
429 |
+
self, h: Tensor, return_loc: bool = True, t: Optional[float] = None
|
430 |
+
) -> Tuple[Tensor, Tensor]:
|
431 |
if return_loc:
|
432 |
x, logscale = self.forward(h)
|
433 |
else:
|
|
|
438 |
|
439 |
|
440 |
class HVAE(nn.Module):
|
441 |
+
def __init__(self, args: Hparams):
|
442 |
super().__init__()
|
443 |
args.vr = "light" if "ukbb" in args.hps else None # hacky
|
444 |
self.encoder = Encoder(args)
|
|
|
449 |
NotImplementedError(f"{args.x_like} not implemented.")
|
450 |
self.cond_prior = args.cond_prior
|
451 |
self.free_bits = args.kl_free_bits
|
452 |
+
self.register_buffer("log2", torch.tensor(2.0).log())
|
453 |
|
454 |
+
def forward(self, x: Tensor, parents: Tensor, beta: int = 1) -> Dict[str, Tensor]:
|
455 |
+
#print(f'Encoder Input:')
|
456 |
+
#print(type(x))
|
457 |
+
#print(x.shape)
|
458 |
acts = self.encoder(x)
|
459 |
+
#print(type(acts))
|
460 |
+
#for key, i in acts.items():
|
461 |
+
#print(f'Encoder output key: {key}')
|
462 |
+
#print(type(i))
|
463 |
+
#print(i.shape)
|
464 |
+
|
465 |
+
#print('Parents')
|
466 |
+
#print(parents.shape)
|
467 |
h, stats = self.decoder(parents=parents, x=acts)
|
468 |
+
#print('Decoder output shape: ', h.shape)
|
469 |
+
#print('Stats: ')
|
470 |
+
#for stat in stats:
|
471 |
+
#for key, i in stat.items():
|
472 |
+
#print(f'Key: {key}')
|
473 |
+
#print(type(i))
|
474 |
+
#print(i.shape)
|
475 |
+
|
476 |
nll_pp = self.likelihood.nll(h, x)
|
477 |
if self.free_bits > 0:
|
478 |
free_bits = torch.tensor(self.free_bits).type_as(nll_pp)
|
|
|
483 |
).sum()
|
484 |
else:
|
485 |
kl_pp = torch.zeros_like(nll_pp)
|
486 |
+
for _, stat in enumerate(stats):
|
487 |
kl_pp += stat["kl"].sum(dim=(1, 2, 3))
|
488 |
kl_pp = kl_pp / np.prod(x.shape[1:]) # per pixel
|
489 |
+
kl_pp = kl_pp.mean() # / self.log2
|
490 |
+
nll_pp = nll_pp.mean() # / self.log2
|
491 |
+
nelbo = nll_pp + beta * kl_pp # negative elbo (free energy)
|
492 |
+
return dict(elbo=nelbo, nll=nll_pp, kl=kl_pp)
|
493 |
+
|
494 |
+
def sample(
|
495 |
+
self, parents: Tensor, return_loc: bool = True, t: Optional[float] = None
|
496 |
+
) -> Tuple[Tensor, Tensor]:
|
497 |
h, _ = self.decoder(parents=parents, t=t)
|
498 |
return self.likelihood.sample(h, return_loc, t=t)
|
499 |
|
500 |
+
def abduct(
|
501 |
+
self,
|
502 |
+
x: Tensor,
|
503 |
+
parents: Tensor,
|
504 |
+
cf_parents: Optional[Tensor] = None,
|
505 |
+
alpha: float = 0.5,
|
506 |
+
t: Optional[float] = None,
|
507 |
+
) -> List[Tensor]:
|
508 |
acts = self.encoder(x)
|
509 |
_, q_stats = self.decoder(
|
510 |
x=acts, parents=parents, abduct=True, t=t
|
|
|
531 |
# Option1: mixture distribution: r(z_i | z_{<i}, x, pa, pa*)
|
532 |
# = a*q(z_i | z_{<i}, x, pa) + (1-a)*p(z_i | z_{<i}, pa*)
|
533 |
r_loc = alpha * q_loc + (1 - alpha) * p_loc
|
534 |
+
r_var = (
|
535 |
+
alpha**2 * q_scale.pow(2) + (1 - alpha)**2 * p_var
|
536 |
+
) # assumes independence
|
537 |
# r_var = a*(q_loc.pow(2) + q_var) + (1-a)*(p_loc.pow(2) + p_var) - r_loc.pow(2)
|
538 |
|
539 |
# # Option 2: precision weighted distribution
|
|
|
551 |
else:
|
552 |
return q_stats # zs
|
553 |
|
554 |
+
def forward_latents(
|
555 |
+
self, latents: List[Tensor], parents: Tensor, t: Optional[float] = None
|
556 |
+
) -> Tuple[Tensor, Tensor]:
|
557 |
h, _ = self.decoder(latents=latents, parents=parents, t=t)
|
558 |
return self.likelihood.sample(h, t=t)
|