--- title: Callbacks keywords: fastai sidebar: home_sidebar summary: "API details." --- 
%load_ext autoreload
%autoreload 2
%matplotlib inline

class TorchCallback[source]

TorchCallback()

class BasicConfig[source]

BasicConfig(priority=0) :: TorchCallback

Handles basic model tasks like putting the model on the GPU and switching between train and eval modes.

class StatsHandler[source]

StatsHandler(priority=5) :: TorchCallback

This updates metrics at the end of each epoch to account for potentially varying batch sizes.

class MetricPrinter[source]

MetricPrinter(priority=10) :: TorchCallback

Prints metrics at the end of each epoch. This is one of the default callbacks provided in BaseModel - it does not need to be passed in explicitly.

class EarlyStopper[source]

EarlyStopper(goal:('max', 'min'), metric='loss', min_improvement=0.0, patience=3, priority=15) :: TorchCallback

class PerformanceThreshold[source]

PerformanceThreshold(metric, goal:('min', 'max'), threshold, skip_epochs=0, split:('train', 'val')='val', priority=15) :: TorchCallback

class ModelCheckpoint[source]

ModelCheckpoint(metric='loss', goal:('max', 'min')='min', priority=25) :: TorchCallback

class MetricHistory[source]

MetricHistory(fname='history.csv', plot_fname='history.png', priority=90) :: TorchCallback

Separate from StatsHandler in case we don't want to log outputs.

class S3Uploader[source]

S3Uploader(prefix, priority=95) :: TorchCallback

Upload model and logs to S3 when training finishes.

class EC2Closer[source]

EC2Closer(timeout=5, priority=100) :: TorchCallback

class ModelUnfreezer[source]

ModelUnfreezer(i2n, unfreeze_type:('groups', 'layers')='groups', mode:('batch', 'epoch')='epoch', priority=25) :: TorchCallback

Gradually unfreeze a model during training.

class SchedulerMixin[source]

SchedulerMixin() :: TorchCallback

class CosineLRScheduler[source]

CosineLRScheduler(warm=0.3, restarts=False, cycle_len=5, cycle_decay=0.0, min_lr=None, verbose=False, priority=10) :: SchedulerMixin

Learning rate scheduler that makes updates each batch.