Important: This notebook will only work with fastai-0.7.x. Do not try to run any fastai-1.x code from this path in the repository because it will load fastai-0.7.x
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%matplotlib inline
%reload_ext autoreload
%autoreload 2
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?re.compile
Super resolution data¶
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from fastai.conv_learner import *
from pathlib import Path
torch.cuda.set_device(0)
torch.backends.cudnn.benchmark=True
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PATH = Path('data/imagenet')
PATH_TRN = PATH/'train'
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fnames_full,label_arr_full,all_labels = folder_source(PATH, 'train')
fnames_full = ['/'.join(Path(fn).parts[-2:]) for fn in fnames_full]
list(zip(fnames_full[:5],label_arr_full[:5]))
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[('n01440764/n01440764_9627.JPEG', 0),
('n01440764/n01440764_9609.JPEG', 0),
('n01440764/n01440764_5176.JPEG', 0),
('n01440764/n01440764_6936.JPEG', 0),
('n01440764/n01440764_4005.JPEG', 0)]
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all_labels[:5]
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['n01440764', 'n01443537', 'n01484850', 'n01491361', 'n01494475']
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np.random.seed(42)
# keep_pct = 1.
keep_pct = 0.02
keeps = np.random.rand(len(fnames_full)) < keep_pct
fnames = np.array(fnames_full, copy=False)[keeps]
label_arr = np.array(label_arr_full, copy=False)[keeps]
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arch = vgg16
sz_lr = 72
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# scale,bs = 2,64
scale,bs = 4,24
sz_hr = sz_lr*scale
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class MatchedFilesDataset(FilesDataset):
def __init__(self, fnames, y, transform, path):
self.y=y
assert(len(fnames)==len(y))
super().__init__(fnames, transform, path)
def get_y(self, i): return open_image(os.path.join(self.path, self.y[i]))
def get_c(self): return 0
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aug_tfms = [RandomDihedral(tfm_y=TfmType.PIXEL)]
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val_idxs = get_cv_idxs(len(fnames), val_pct=min(0.01/keep_pct, 0.1))
((val_x,trn_x),(val_y,trn_y)) = split_by_idx(val_idxs, np.array(fnames), np.array(fnames))
len(val_x),len(trn_x)
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(2558, 23026)
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img_fn = PATH/'train'/'n01558993'/'n01558993_9684.JPEG'
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tfms = tfms_from_model(arch, sz_lr, tfm_y=TfmType.PIXEL, aug_tfms=aug_tfms, sz_y=sz_hr)
datasets = ImageData.get_ds(MatchedFilesDataset, (trn_x,trn_y), (val_x,val_y), tfms, path=PATH_TRN)
md = ImageData(PATH, datasets, bs, num_workers=16, classes=None)
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denorm = md.val_ds.denorm
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def show_img(ims, idx, figsize=(5,5), normed=True, ax=None):
if ax is None: fig,ax = plt.subplots(figsize=figsize)
if normed: ims = denorm(ims)
else: ims = np.rollaxis(to_np(ims),1,4)
ax.imshow(np.clip(ims,0,1)[idx])
ax.axis('off')
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x,y = next(iter(md.val_dl))
x.size(),y.size()
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(torch.Size([64, 3, 72, 72]), torch.Size([64, 3, 144, 144]))
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idx=1
fig,axes = plt.subplots(1, 2, figsize=(9,5))
show_img(x,idx, ax=axes[0])
show_img(y,idx, ax=axes[1])
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batches = [next(iter(md.aug_dl)) for i in range(9)]
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fig, axes = plt.subplots(3, 6, figsize=(18, 9))
for i,(x,y) in enumerate(batches):
show_img(x,idx, ax=axes.flat[i*2])
show_img(y,idx, ax=axes.flat[i*2+1])
Model¶
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def conv(ni, nf, kernel_size=3, actn=True):
layers = [nn.Conv2d(ni, nf, kernel_size, padding=kernel_size//2)]
if actn: layers.append(nn.ReLU(True))
return nn.Sequential(*layers)
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class ResSequential(nn.Module):
def __init__(self, layers, res_scale=1.0):
super().__init__()
self.res_scale = res_scale
self.m = nn.Sequential(*layers)
def forward(self, x):
x = x + self.m(x) * self.res_scale
return x
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def res_block(nf):
return ResSequential(
[conv(nf, nf), conv(nf, nf, actn=False)],
0.1)
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def upsample(ni, nf, scale):
layers = []
for i in range(int(math.log(scale,2))):
layers += [conv(ni, nf*4), nn.PixelShuffle(2)]
return nn.Sequential(*layers)
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class SrResnet(nn.Module):
def __init__(self, nf, scale):
super().__init__()
features = [conv(3, 64)]
for i in range(8): features.append(res_block(64))
features += [conv(64,64), upsample(64, 64, scale),
nn.BatchNorm2d(64),
conv(64, 3, actn=False)]
self.features = nn.Sequential(*features)
def forward(self, x): return self.features(x)
Pixel loss¶
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m = to_gpu(SrResnet(64, scale))
m = nn.DataParallel(m, [0,2])
learn = Learner(md, SingleModel(m), opt_fn=optim.Adam)
learn.crit = F.mse_loss
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learn.lr_find(start_lr=1e-5, end_lr=10000)
learn.sched.plot()
A Jupyter Widget
31%|███▏ | 225/720 [00:24<00:53, 9.19it/s, loss=0.0482]
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lr=2e-3
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learn.fit(lr, 1, cycle_len=1, use_clr_beta=(40,10))
A Jupyter Widget
2%|▏ | 15/720 [00:02<01:52, 6.25it/s, loss=0.042]
epoch trn_loss val_loss
0 0.007431 0.008192
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[array([0.00819])]
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x,y = next(iter(md.val_dl))
preds = learn.model(VV(x))
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idx=4
show_img(y,idx,normed=False)
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show_img(preds,idx,normed=False);
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show_img(x,idx,normed=True);
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x,y = next(iter(md.val_dl))
preds = learn.model(VV(x))
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show_img(y,idx,normed=False)
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show_img(preds,idx,normed=False);
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show_img(x,idx);
Perceptual loss¶
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def icnr(x, scale=2, init=nn.init.kaiming_normal):
new_shape = [int(x.shape[0] / (scale ** 2))] + list(x.shape[1:])
subkernel = torch.zeros(new_shape)
subkernel = init(subkernel)
subkernel = subkernel.transpose(0, 1)
subkernel = subkernel.contiguous().view(subkernel.shape[0],
subkernel.shape[1], -1)
kernel = subkernel.repeat(1, 1, scale ** 2)
transposed_shape = [x.shape[1]] + [x.shape[0]] + list(x.shape[2:])
kernel = kernel.contiguous().view(transposed_shape)
kernel = kernel.transpose(0, 1)
return kernel
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m_vgg = vgg16(True)
blocks = [i-1 for i,o in enumerate(children(m_vgg))
if isinstance(o,nn.MaxPool2d)]
blocks, [m_vgg[i] for i in blocks]
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([5, 12, 22, 32, 42], [ReLU(inplace), ReLU(inplace), ReLU(inplace), ReLU(inplace), ReLU(inplace)])
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vgg_layers = children(m_vgg)[:13]
m_vgg = nn.Sequential(*vgg_layers).cuda().eval()
set_trainable(m_vgg, False)
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def flatten(x): return x.view(x.size(0), -1)
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class SaveFeatures():
features=None
def __init__(self, m): self.hook = m.register_forward_hook(self.hook_fn)
def hook_fn(self, module, input, output): self.features = output
def remove(self): self.hook.remove()
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class FeatureLoss(nn.Module):
def __init__(self, m, layer_ids, layer_wgts):
super().__init__()
self.m,self.wgts = m,layer_wgts
self.sfs = [SaveFeatures(m[i]) for i in layer_ids]
def forward(self, input, target, sum_layers=True):
self.m(VV(target.data))
res = [F.l1_loss(input,target)/100]
targ_feat = [V(o.features.data.clone()) for o in self.sfs]
self.m(input)
res += [F.l1_loss(flatten(inp.features),flatten(targ))*wgt
for inp,targ,wgt in zip(self.sfs, targ_feat, self.wgts)]
if sum_layers: res = sum(res)
return res
def close(self):
for o in self.sfs: o.remove()
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m = SrResnet(64, scale)
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conv_shuffle = m.features[10][0][0]
kernel = icnr(conv_shuffle.weight, scale=scale)
conv_shuffle.weight.data.copy_(kernel);
/home/jhoward/anaconda3/lib/python3.6/site-packages/ipykernel_launcher.py:4: UserWarning: nn.init.kaiming_normal is now deprecated in favor of nn.init.kaiming_normal_. after removing the cwd from sys.path.
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conv_shuffle = m.features[10][2][0]
kernel = icnr(conv_shuffle.weight, scale=scale)
conv_shuffle.weight.data.copy_(kernel);
/home/jhoward/anaconda3/lib/python3.6/site-packages/ipykernel_launcher.py:4: UserWarning: nn.init.kaiming_normal is now deprecated in favor of nn.init.kaiming_normal_. after removing the cwd from sys.path.
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m = to_gpu(m)
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learn = Learner(md, SingleModel(m), opt_fn=optim.Adam)
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t = torch.load(learn.get_model_path('sr-samp0'), map_location=lambda storage, loc: storage)
learn.model.load_state_dict(t, strict=False)
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learn.freeze_to(999)
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for i in range(10,13): set_trainable(m.features[i], True)
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lr=6e-3
wd=1e-7
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learn.fit(lr, 1, cycle_len=1, wds=wd, use_clr=(20,10))
HBox(children=(IntProgress(value=0, description='Epoch', max=1), HTML(value='')))
epoch trn_loss val_loss
0 0.097629 0.091069
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[0.09106878512207654]
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learn.crit = FeatureLoss(m_vgg, blocks[:2], [0.26,0.74])
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learn.lr_find(1e-4, 1., wds=wd, linear=True)
HBox(children=(IntProgress(value=0, description='Epoch', max=1), HTML(value='')))
19%|█▊ | 178/960 [01:28<06:28, 2.01it/s, loss=0.141]
--------------------------------------------------------------------------- KeyboardInterrupt Traceback (most recent call last) <ipython-input-36-5feb8d75bbd0> in <module>() ----> 1 learn.lr_find(1e-4, 1., wds=wd, linear=True) /data1/jhoward/git/fastai/courses/dl2/fastai/learner.py in lr_find(self, start_lr, end_lr, wds, linear, **kwargs) 328 layer_opt = self.get_layer_opt(start_lr, wds) 329 self.sched = LR_Finder(layer_opt, len(self.data.trn_dl), end_lr, linear=linear) --> 330 self.fit_gen(self.model, self.data, layer_opt, 1, **kwargs) 331 self.load('tmp') 332 /data1/jhoward/git/fastai/courses/dl2/fastai/learner.py in fit_gen(self, model, data, layer_opt, n_cycle, cycle_len, cycle_mult, cycle_save_name, best_save_name, use_clr, use_clr_beta, metrics, callbacks, use_wd_sched, norm_wds, wds_sched_mult, use_swa, swa_start, swa_eval_freq, **kwargs) 232 metrics=metrics, callbacks=callbacks, reg_fn=self.reg_fn, clip=self.clip, fp16=self.fp16, 233 swa_model=self.swa_model if use_swa else None, swa_start=swa_start, --> 234 swa_eval_freq=swa_eval_freq, **kwargs) 235 236 def get_layer_groups(self): return self.models.get_layer_groups() /data1/jhoward/git/fastai/courses/dl2/fastai/model.py in fit(model, data, n_epochs, opt, crit, metrics, callbacks, stepper, swa_model, swa_start, swa_eval_freq, **kwargs) 127 batch_num += 1 128 for cb in callbacks: cb.on_batch_begin() --> 129 loss = model_stepper.step(V(x),V(y), epoch) 130 avg_loss = avg_loss * avg_mom + loss * (1-avg_mom) 131 debias_loss = avg_loss / (1 - avg_mom**batch_num) /data1/jhoward/git/fastai/courses/dl2/fastai/model.py in step(self, xs, y, epoch) 50 if self.fp16: self.m.zero_grad() 51 else: self.opt.zero_grad() ---> 52 loss = raw_loss = self.crit(output, y) 53 if self.loss_scale != 1: assert(self.fp16); loss = loss*self.loss_scale 54 if self.reg_fn: loss = self.reg_fn(output, xtra, raw_loss) ~/anaconda3/lib/python3.6/site-packages/torch/nn/modules/module.py in __call__(self, *input, **kwargs) 489 result = self._slow_forward(*input, **kwargs) 490 else: --> 491 result = self.forward(*input, **kwargs) 492 for hook in self._forward_hooks.values(): 493 hook_result = hook(self, input, result) <ipython-input-26-e111310935a1> in forward(self, input, target, sum_layers) 11 self.m(input) 12 res += [F.l1_loss(flatten(inp.features),flatten(targ))*wgt ---> 13 for inp,targ,wgt in zip(self.sfs, targ_feat, self.wgts)] 14 if sum_layers: res = sum(res) 15 return res <ipython-input-26-e111310935a1> in <listcomp>(.0) 11 self.m(input) 12 res += [F.l1_loss(flatten(inp.features),flatten(targ))*wgt ---> 13 for inp,targ,wgt in zip(self.sfs, targ_feat, self.wgts)] 14 if sum_layers: res = sum(res) 15 return res ~/anaconda3/lib/python3.6/site-packages/torch/nn/functional.py in l1_loss(input, target, size_average, reduce) 1556 """ 1557 return _pointwise_loss(lambda a, b: torch.abs(a - b), torch._C._nn.l1_loss, -> 1558 input, target, size_average, reduce) 1559 1560 ~/anaconda3/lib/python3.6/site-packages/torch/nn/functional.py in _pointwise_loss(lambd, lambd_optimized, input, target, size_average, reduce) 1535 return torch.mean(d) if size_average else torch.sum(d) 1536 else: -> 1537 return lambd_optimized(input, target, size_average, reduce) 1538 1539 KeyboardInterrupt:
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learn.load('tmp')
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learn.sched.plot(0, n_skip_end=1)
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learn.save('sr-samp0')
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learn.unfreeze()
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learn.fit(lr, 1, cycle_len=1, wds=wd, use_clr=(20,10))
HBox(children=(IntProgress(value=0, description='Epoch', max=1), HTML(value='')))
epoch trn_loss val_loss
0 0.063747 0.060955
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[0.060954763361072986]
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learn.fit(lr, 1, cycle_len=2, wds=wd, use_clr=(20,10))
HBox(children=(IntProgress(value=0, description='Epoch', max=2), HTML(value='')))
epoch trn_loss val_loss
0 0.059319 0.058087
1 0.057485 0.056862
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[0.05686224508299503]
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learn.fit(lr, 1, cycle_len=2, wds=wd, use_clr=(20,10))
HBox(children=(IntProgress(value=0, description='Epoch', max=2), HTML(value='')))
epoch trn_loss val_loss
0 0.066028 0.064855
1 0.063048 0.062271
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[0.06227088433583329]
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learn.sched.plot_loss()
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learn.load('sr-samp1')
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learn.save('sr-samp1')
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learn.load('sr-samp1')
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lr=3e-3
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learn.fit(lr, 1, cycle_len=1, wds=wd, use_clr=(20,10))
HBox(children=(IntProgress(value=0, description='Epoch', max=1), HTML(value='')))
epoch trn_loss val_loss
0 0.069054 0.06638
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[array([0.06638])]
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learn.save('sr-samp2')
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learn.unfreeze()
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learn.load('sr-samp2')
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learn.fit(lr/3, 1, cycle_len=1, wds=wd, use_clr=(20,10))
HBox(children=(IntProgress(value=0, description='Epoch', max=1), HTML(value='')))
epoch trn_loss val_loss
0 0.06042 0.057613
Out[ ]:
[array([0.05761])]
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learn.save('sr1')
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def plot_ds_img(idx, ax=None, figsize=(7,7), normed=True):
if ax is None: fig,ax = plt.subplots(figsize=figsize)
im = md.val_ds[idx][0]
if normed: im = denorm(im)[0]
else: im = np.rollaxis(to_np(im),0,3)
ax.imshow(im)
ax.axis('off')
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fig,axes=plt.subplots(6,6,figsize=(20,20))
for i,ax in enumerate(axes.flat): plot_ds_img(i+200,ax=ax, normed=True)
Clipping input data to the valid range for imshow with RGB data ([0..1] for floats or [0..255] for integers).
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x,y=md.val_ds[201]
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y=y[None]
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learn.model.eval()
preds = learn.model(VV(x[None]))
x.shape,y.shape,preds.shape
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((3, 72, 72), (1, 3, 288, 288), torch.Size([1, 3, 288, 288]))
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learn.crit(preds, V(y), sum_layers=False)
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[tensor(1.00000e-03 *
2.0065, device='cuda:0'), tensor(1.00000e-02 *
2.2847, device='cuda:0'), tensor(1.00000e-02 *
4.8297, device='cuda:0')]
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learn.crit(preds, V(y), sum_layers=False)
Out[ ]:
[tensor(1.00000e-03 *
2.1613, device='cuda:0'), tensor(1.00000e-03 *
4.7700, device='cuda:0'), tensor(1.00000e-02 *
4.4875, device='cuda:0'), tensor(1.00000e-02 *
1.0256, device='cuda:0')]
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learn.crit.close()
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_,axes=plt.subplots(1,2,figsize=(14,7))
show_img(x[None], 0, ax=axes[0])
show_img(preds,0, normed=True, ax=axes[1])
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_,axes=plt.subplots(1,2,figsize=(14,7))
show_img(x[None], 0, ax=axes[0])
show_img(preds,0, normed=True, ax=axes[1])
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_,axes=plt.subplots(1,2,figsize=(14,7))
show_img(x[None], 0, ax=axes[0])
show_img(preds,0, normed=True, ax=axes[1])
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