Source code for mxnet.model
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# pylint: disable=fixme, invalid-name, too-many-arguments, too-many-locals, too-many-lines
# pylint: disable=too-many-branches, too-many-statements
"""MXNet model module"""
import os
import time
import logging
import warnings
from collections import namedtuple
import numpy as np
from . import io
from . import ndarray as nd
from . import symbol as sym
from . import optimizer as opt
from . import metric
from . import kvstore as kvs
from .context import Context, cpu
from .initializer import Uniform
from .optimizer import get_updater
from .executor_manager import DataParallelExecutorManager, _check_arguments, _load_data
from .io import DataDesc
from .base import mx_real_t
BASE_ESTIMATOR = object
try:
from sklearn.base import BaseEstimator
BASE_ESTIMATOR = BaseEstimator
except ImportError:
SKLEARN_INSTALLED = False
# Parameter to pass to batch_end_callback
BatchEndParam = namedtuple('BatchEndParams',
['epoch',
'nbatch',
'eval_metric',
'locals'])
def _create_sparse_kvstore(kvstore):
"""Create kvstore assuming some parameters' storage types are row_sparse.
Parameters
----------
kvstore : KVStore or str
The kvstore.
Returns
-------
kvstore : KVStore
update_on_kvstore : bool. Always True.
"""
# always update on kvstore
if isinstance(kvstore, kvs.KVStore):
kv = kvstore
elif isinstance(kvstore, str):
kv = kvs.create(kvstore)
else:
raise TypeError("Cannot create '%s' KVStore with row_sparse parameters. "
"The type must be KVStore or str." % kvstore)
assert kv.is_capable(kvs.KVStoreBase.OPTIMIZER), \
"KVStore with sparse weight requires optimizer support. " \
"However, type(kv) does not support optimizer. " \
"Please consider other kvstore backends (e.g. dist_device) instead."
return (kv, True)
def _create_kvstore(kvstore, num_device, arg_params):
"""Create kvstore
This function select and create a proper kvstore if given the kvstore type.
Parameters
----------
kvstore : KVStore or str
The kvstore.
num_device : int
The number of devices
arg_params : dict of str to `NDArray`.
Model parameter, dict of name to `NDArray` of net's weights.
"""
update_on_kvstore = bool(int(os.getenv('MXNET_UPDATE_ON_KVSTORE', "1")))
if kvstore is None:
kv = None
elif isinstance(kvstore, kvs.KVStoreBase):
kv = kvstore
elif isinstance(kvstore, str):
# create kvstore using the string type
if num_device == 1 and 'dist' not in kvstore:
# no need to use kv for single device and single machine
kv = None
else:
kv = kvs.create(kvstore)
if kvstore == 'local':
# automatically select a proper local
max_size = max(np.prod(param.shape) for param in
arg_params.values())
if max_size > 1024 * 1024 * 16:
update_on_kvstore = False
else:
raise TypeError('kvstore must be KVStore, str or None')
if kv is None:
update_on_kvstore = False
else:
update_on_kvstore &= kv.is_capable(kvs.KVStoreBase.OPTIMIZER)
return (kv, update_on_kvstore)
def _initialize_kvstore(kvstore, param_arrays, arg_params, param_names, update_on_kvstore):
"""Initialize kvstore"""
for idx, param_on_devs in enumerate(param_arrays):
name = param_names[idx]
if not update_on_kvstore or arg_params[name].stype != 'default':
kvstore.init(name, arg_params[name])
else:
kvstore.broadcast(name, arg_params[name], out=param_on_devs)
def _update_params_on_kvstore_nccl(param_arrays, grad_arrays, kvstore, param_names):
"""Perform update of param_arrays from grad_arrays on NCCL kvstore."""
valid_indices = [index for index, grad_list in
enumerate(grad_arrays) if grad_list[0] is not None]
valid_grad_arrays = [grad_arrays[i] for i in valid_indices]
valid_param_arrays = [param_arrays[i] for i in valid_indices]
valid_param_names = [param_names[i] for i in valid_indices]
size = len(valid_grad_arrays)
start = 0
# Use aggregation by default only with NCCL
default_batch = '16'
batch = int(os.getenv('MXNET_UPDATE_AGGREGATION_SIZE', default_batch))
while start < size:
end = start + batch if start + batch < size else size
# push gradient, priority is negative index
# pull back the weights
kvstore.pushpull(valid_param_names[start:end], valid_grad_arrays[start:end],
out=valid_param_arrays[start:end], priority=-start)
start = end
def _update_params_on_kvstore(param_arrays, grad_arrays, kvstore, param_names):
"""Perform update of param_arrays from grad_arrays on kvstore."""
for index, pair in enumerate(zip(param_arrays, grad_arrays)):
arg_list, grad_list = pair
if grad_list[0] is None:
continue
name = param_names[index]
# push gradient, priority is negative index
# pull back the weights
if grad_list[0].stype == 'default' and arg_list[0].stype == 'default':
kvstore.pushpull(name, grad_list, out=arg_list, priority=-index)
else:
kvstore.push(name, grad_list, priority=-index)
kvstore.pull(name, out=arg_list, priority=-index)
def _update_params(param_arrays, grad_arrays, updater, num_device,
kvstore=None, param_names=None):
"""Perform update of param_arrays from grad_arrays not on kvstore."""
updates = [[] for _ in range(num_device)]
for i, pair in enumerate(zip(param_arrays, grad_arrays)):
arg_list, grad_list = pair
if grad_list[0] is None:
continue
index = i
if kvstore:
name = param_names[index]
# push gradient, priority is negative index
if grad_list[0].stype == 'default' and arg_list[0].stype == 'default':
kvstore.pushpull(name, grad_list, priority=-index)
else:
kvstore.push(name, grad_list, priority=-index)
kvstore.pull(name, out=grad_list, priority=-index)
for k, p in enumerate(zip(arg_list, grad_list)):
# faked an index here, to make optimizer create diff
# state for the same index but on diff devs, TODO(mli)
# use a better solution later
w, g = p
updates[k].append((index*num_device+k, g, w))
for dev_updates in updates:
# update params if param_arrays and grad_arrays are not empty
if dev_updates:
i, w, g = zip(*dev_updates)
updater(i, w, g)
def _multiple_callbacks(callbacks, *args, **kwargs):
"""Sends args and kwargs to any configured callbacks.
This handles the cases where the 'callbacks' variable
is ``None``, a single function, or a list.
"""
if isinstance(callbacks, list):
for cb in callbacks:
cb(*args, **kwargs)
return
if callbacks:
callbacks(*args, **kwargs)
def _train_multi_device(symbol, ctx, arg_names, param_names, aux_names,
arg_params, aux_params,
begin_epoch, end_epoch, epoch_size, optimizer,
kvstore, update_on_kvstore,
train_data, eval_data=None, eval_metric=None,
epoch_end_callback=None, batch_end_callback=None,
logger=None, work_load_list=None, monitor=None,
eval_end_callback=None,
eval_batch_end_callback=None, sym_gen=None):
"""Internal training function on multiple devices.
This function will also work for single device as well.
Parameters
----------
symbol : Symbol
The network configuration.
ctx : list of Context
The training devices.
arg_names: list of str
Name of all arguments of the network.
param_names: list of str
Name of all trainable parameters of the network.
aux_names: list of str
Name of all auxiliary states of the network.
arg_params : dict of str to NDArray
Model parameter, dict of name to NDArray of net's weights.
aux_params : dict of str to NDArray
Model parameter, dict of name to NDArray of net's auxiliary states.
begin_epoch : int
The begining training epoch.
end_epoch : int
The end training epoch.
epoch_size : int, optional
Number of batches in a epoch. In default, it is set to
``ceil(num_train_examples / batch_size)``.
optimizer : Optimizer
The optimization algorithm
train_data : DataIter
Training data iterator.
eval_data : DataIter
Validation data iterator.
eval_metric : EvalMetric
An evaluation function or a list of evaluation functions.
epoch_end_callback : callable(epoch, symbol, arg_params, aux_states)
A callback that is invoked at end of each epoch.
This can be used to checkpoint model each epoch.
batch_end_callback : callable(BatchEndParams)
A callback that is invoked at end of each batch.
This can be used to measure speed, get result from evaluation metric. etc.
kvstore : KVStore
The KVStore.
update_on_kvstore : bool
Whether or not perform weight updating on kvstore.
logger : logging logger
When not specified, default logger will be used.
work_load_list : list of float or int, optional
The list of work load for different devices,
in the same order as ``ctx``.
monitor : Monitor, optional
Monitor installed to executor,
for monitoring outputs, weights, and gradients for debugging.
Notes
-----
- This function will inplace update the NDArrays in `arg_params` and `aux_states`.
"""
if logger is None:
logger = logging
executor_manager = DataParallelExecutorManager(symbol=symbol,
sym_gen=sym_gen,
ctx=ctx,
train_data=train_data,
param_names=param_names,
arg_names=arg_names,
aux_names=aux_names,
work_load_list=work_load_list,
logger=logger)
if monitor:
executor_manager.install_monitor(monitor)
executor_manager.set_params(arg_params, aux_params)
if not update_on_kvstore:
updater = get_updater(optimizer)
else:
kvstore.set_optimizer(optimizer)
if kvstore:
_initialize_kvstore(kvstore=kvstore,
param_arrays=executor_manager.param_arrays,
arg_params=arg_params,
param_names=executor_manager.param_names,
update_on_kvstore=update_on_kvstore)
# Now start training
train_data.reset()
for epoch in range(begin_epoch, end_epoch):
# Training phase
tic = time.time()
eval_metric.reset()
nbatch = 0
# Iterate over training data.
while True:
do_reset = True
for data_batch in train_data:
executor_manager.load_data_batch(data_batch)
if monitor is not None:
monitor.tic()
executor_manager.forward(is_train=True)
executor_manager.backward()
if update_on_kvstore:
if 'nccl' in kvstore.type:
_update_params_on_kvstore_nccl(executor_manager.param_arrays,
executor_manager.grad_arrays,
kvstore, executor_manager.param_names)
else:
_update_params_on_kvstore(executor_manager.param_arrays,
executor_manager.grad_arrays,
kvstore, executor_manager.param_names)
else:
_update_params(executor_manager.param_arrays,
executor_manager.grad_arrays,
updater=updater,
num_device=len(ctx),
kvstore=kvstore,
param_names=executor_manager.param_names)
if monitor is not None:
monitor.toc_print()
# evaluate at end, so we can lazy copy
executor_manager.update_metric(eval_metric, data_batch.label)
nbatch += 1
# batch callback (for print purpose)
if batch_end_callback is not None:
batch_end_params = BatchEndParam(epoch=epoch,
nbatch=nbatch,
eval_metric=eval_metric,
locals=locals())
_multiple_callbacks(batch_end_callback, batch_end_params)
# this epoch is done possibly earlier
if epoch_size is not None and nbatch >= epoch_size:
do_reset = False
break
if do_reset:
logger.info('Epoch[%d] Resetting Data Iterator', epoch)
train_data.reset()
# this epoch is done
if epoch_size is None or nbatch >= epoch_size:
break
toc = time.time()
logger.info('Epoch[%d] Time cost=%.3f', epoch, (toc - tic))
if epoch_end_callback or epoch + 1 == end_epoch:
executor_manager.copy_to(arg_params, aux_params)
_multiple_callbacks(epoch_end_callback, epoch, symbol, arg_params, aux_params)
# evaluation
if eval_data:
eval_metric.reset()
eval_data.reset()
total_num_batch = 0
for i, eval_batch in enumerate(eval_data):
executor_manager.load_data_batch(eval_batch)
executor_manager.forward(is_train=False)
executor_manager.update_metric(eval_metric, eval_batch.label)
if eval_batch_end_callback is not None:
batch_end_params = BatchEndParam(epoch=epoch,
nbatch=i,
eval_metric=eval_metric,
locals=locals())
_multiple_callbacks(eval_batch_end_callback, batch_end_params)
total_num_batch += 1
if eval_end_callback is not None:
eval_end_params = BatchEndParam(epoch=epoch,
nbatch=total_num_batch,
eval_metric=eval_metric,
locals=locals())
_multiple_callbacks(eval_end_callback, eval_end_params)
eval_data.reset()
# end of all epochs
[docs]def save_checkpoint(prefix, epoch, symbol, arg_params, aux_params, remove_amp_cast=True):
"""Checkpoint the model data into file.
Parameters
----------
prefix : str
Prefix of model name.
epoch : int
The epoch number of the model.
symbol : Symbol
The input Symbol.
arg_params : dict of str to NDArray
Model parameter, dict of name to NDArray of net's weights.
aux_params : dict of str to NDArray
Model parameter, dict of name to NDArray of net's auxiliary states.
remove_amp_cast : bool, optional
Whether to remove the amp_cast and amp_multicast operators, before saving the model.
Notes
-----
- ``prefix-symbol.json`` will be saved for symbol.
- ``prefix-epoch.params`` will be saved for parameters.
"""
if symbol is not None:
symbol.save('%s-symbol.json' % prefix, remove_amp_cast=remove_amp_cast)
save_dict = {('arg:%s' % k) : v.as_in_context(cpu()) for k, v in arg_params.items()}
save_dict.update({('aux:%s' % k) : v.as_in_context(cpu()) for k, v in aux_params.items()})
param_name = '%s-%04d.params' % (prefix, epoch)
nd.save(param_name, save_dict)
logging.info('Saved checkpoint to \"%s\"', param_name)
[docs]def load_params(prefix, epoch):
"""Load params from a file
"""
save_dict = nd.load("%s-%04d.params" % (prefix, epoch))
arg_params = {}
aux_params = {}
if not save_dict:
logging.warning("Params file '%s' is empty", '%s-%04d.params' % (prefix, epoch))
return (arg_params, aux_params)
for k, v in save_dict.items():
tp, name = k.split(":", 1)
if tp == "arg":
arg_params[name] = v
if tp == "aux":
aux_params[name] = v
return (arg_params, aux_params)
[docs]def load_checkpoint(prefix, epoch):
"""Load model checkpoint from file.
Parameters
----------
prefix : str
Prefix of model name.
epoch : int
Epoch number of model we would like to load.
Returns
-------
symbol : Symbol
The symbol configuration of computation network.
arg_params : dict of str to NDArray
Model parameter, dict of name to NDArray of net's weights.
aux_params : dict of str to NDArray
Model parameter, dict of name to NDArray of net's auxiliary states.
Notes
-----
- Symbol will be loaded from ``prefix-symbol.json``.
- Parameters will be loaded from ``prefix-epoch.params``.
"""
symbol = sym.load('%s-symbol.json' % prefix)
arg_params, aux_params = load_params(prefix, epoch)
return (symbol, arg_params, aux_params)
from .callback import LogValidationMetricsCallback # pylint: disable=wrong-import-position
[docs]class FeedForward(BASE_ESTIMATOR):
"""Model class of MXNet for training and predicting feedforward nets.
This class is designed for a single-data single output supervised network.
Parameters
----------
symbol : Symbol
The symbol configuration of computation network.
ctx : Context or list of Context, optional
The device context of training and prediction.
To use multi GPU training, pass in a list of gpu contexts.
num_epoch : int, optional
Training parameter, number of training epochs(epochs).
epoch_size : int, optional
Number of batches in a epoch. In default, it is set to
``ceil(num_train_examples / batch_size)``.
optimizer : str or Optimizer, optional
Training parameter, name or optimizer object for training.
initializer : initializer function, optional
Training parameter, the initialization scheme used.
numpy_batch_size : int, optional
The batch size of training data.
Only needed when input array is numpy.
arg_params : dict of str to NDArray, optional
Model parameter, dict of name to NDArray of net's weights.
aux_params : dict of str to NDArray, optional
Model parameter, dict of name to NDArray of net's auxiliary states.
allow_extra_params : boolean, optional
Whether allow extra parameters that are not needed by symbol
to be passed by aux_params and ``arg_params``.
If this is True, no error will be thrown when ``aux_params`` and ``arg_params``
contain more parameters than needed.
begin_epoch : int, optional
The begining training epoch.
kwargs : dict
The additional keyword arguments passed to optimizer.
"""
def __init__(self, symbol, ctx=None,
num_epoch=None, epoch_size=None, optimizer='sgd',
initializer=Uniform(0.01),
numpy_batch_size=128,
arg_params=None, aux_params=None,
allow_extra_params=False,
begin_epoch=0,
**kwargs):
warnings.warn(
'\033[91mmxnet.model.FeedForward has been deprecated. ' + \
'Please use mxnet.mod.Module instead.\033[0m',
DeprecationWarning, stacklevel=2)
if isinstance(symbol, sym.Symbol):
self.symbol = symbol
self.sym_gen = None
else:
assert(callable(symbol))
self.symbol = None
self.sym_gen = symbol
# model parameters
self.arg_params = arg_params
self.aux_params = aux_params
self.allow_extra_params = allow_extra_params
self.argument_checked = False
if self.sym_gen is None:
self._check_arguments()
# basic configuration
if ctx is None:
ctx = [cpu()]
elif isinstance(ctx, Context):
ctx = [ctx]
self.ctx = ctx
# training parameters
self.num_epoch = num_epoch
self.epoch_size = epoch_size
self.kwargs = kwargs.copy()
self.optimizer = optimizer
self.initializer = initializer
self.numpy_batch_size = numpy_batch_size
# internal helper state
self._pred_exec = None
self.begin_epoch = begin_epoch
def _check_arguments(self):
"""verify the argument of the default symbol and user provided parameters"""
if self.argument_checked:
return
assert(self.symbol is not None)
self.argument_checked = True
# check if symbol contain duplicated names.
_check_arguments(self.symbol)
# rematch parameters to delete useless ones
if self.allow_extra_params:
if self.arg_params:
arg_names = set(self.symbol.list_arguments())
self.arg_params = {k : v for k, v in self.arg_params.items()
if k in arg_names}
if self.aux_params:
aux_names = set(self.symbol.list_auxiliary_states())
self.aux_params = {k : v for k, v in self.aux_params.items()
if k in aux_names}
@staticmethod
def _is_data_arg(name):
"""Check if name is a data argument."""
return name.endswith('data') or name.endswith('label')
def _init_params(self, inputs, overwrite=False):
"""Initialize weight parameters and auxiliary states."""
inputs = [x if isinstance(x, DataDesc) else DataDesc(*x) for x in inputs]
input_shapes = {item.name: item.shape for item in inputs}
arg_shapes, _, aux_shapes = self.symbol.infer_shape(**input_shapes)
assert arg_shapes is not None
input_dtypes = {item.name: item.dtype for item in inputs}
arg_dtypes, _, aux_dtypes = self.symbol.infer_type(**input_dtypes)
assert arg_dtypes is not None
arg_names = self.symbol.list_arguments()
input_names = input_shapes.keys()
param_names = [key for key in arg_names if key not in input_names]
aux_names = self.symbol.list_auxiliary_states()
param_name_attrs = [x for x in zip(arg_names, arg_shapes, arg_dtypes)
if x[0] in param_names]
arg_params = {k : nd.zeros(shape=s, dtype=t)
for k, s, t in param_name_attrs}
aux_name_attrs = [x for x in zip(aux_names, aux_shapes, aux_dtypes)
if x[0] in aux_names]
aux_params = {k : nd.zeros(shape=s, dtype=t)
for k, s, t in aux_name_attrs}
for k, v in arg_params.items():
if self.arg_params and k in self.arg_params and (not overwrite):
arg_params[k][:] = self.arg_params[k][:]
else:
self.initializer(k, v)
for k, v in aux_params.items():
if self.aux_params and k in self.aux_params and (not overwrite):
aux_params[k][:] = self.aux_params[k][:]
else:
self.initializer(k, v)
self.arg_params = arg_params
self.aux_params = aux_params
return (arg_names, list(param_names), aux_names)
def __getstate__(self):
this = self.__dict__.copy()
this['_pred_exec'] = None
return this
def __setstate__(self, state):
self.__dict__.update(state)
def _init_predictor(self, input_shapes, type_dict=None):
"""Initialize the predictor module for running prediction."""
shapes = {name: self.arg_params[name].shape for name in self.arg_params}
shapes.update(dict(input_shapes))
if self._pred_exec is not None:
arg_shapes, _, _ = self.symbol.infer_shape(**shapes)
assert arg_shapes is not None, "Incomplete input shapes"
pred_shapes = [x.shape for x in self._pred_exec.arg_arrays]
if arg_shapes == pred_shapes:
return
# for now only use the first device
pred_exec = self.symbol.simple_bind(
self.ctx[0], grad_req='null', type_dict=type_dict, **shapes)
pred_exec.copy_params_from(self.arg_params, self.aux_params)
_check_arguments(self.symbol)
self._pred_exec = pred_exec
def _init_iter(self, X, y, is_train):
"""Initialize the iterator given input."""
if isinstance(X, (np.ndarray, nd.NDArray)):
if y is None:
if is_train:
raise ValueError('y must be specified when X is numpy.ndarray')
y = np.zeros(X.shape[0])
if not isinstance(y, (np.ndarray, nd.NDArray)):
raise TypeError('y must be ndarray when X is numpy.ndarray')
if X.shape[0] != y.shape[0]:
raise ValueError("The numbers of data points and labels not equal")
if y.ndim == 2 and y.shape[1] == 1:
y = y.flatten()
if y.ndim != 1:
raise ValueError("Label must be 1D or 2D (with 2nd dimension being 1)")
if is_train:
return io.NDArrayIter(X, y, min(X.shape[0], self.numpy_batch_size),
shuffle=is_train, last_batch_handle='roll_over')
else:
return io.NDArrayIter(X, y, min(X.shape[0], self.numpy_batch_size), shuffle=False)
if not isinstance(X, io.DataIter):
raise TypeError('X must be DataIter, NDArray or numpy.ndarray')
return X
def _init_eval_iter(self, eval_data):
"""Initialize the iterator given eval_data."""
if eval_data is None:
return eval_data
if isinstance(eval_data, (tuple, list)) and len(eval_data) == 2:
if eval_data[0] is not None:
if eval_data[1] is None and isinstance(eval_data[0], io.DataIter):
return eval_data[0]
input_data = (np.array(eval_data[0]) if isinstance(eval_data[0], list)
else eval_data[0])
input_label = (np.array(eval_data[1]) if isinstance(eval_data[1], list)
else eval_data[1])
return self._init_iter(input_data, input_label, is_train=True)
else:
raise ValueError("Eval data is NONE")
if not isinstance(eval_data, io.DataIter):
raise TypeError('Eval data must be DataIter, or ' \
'NDArray/numpy.ndarray/list pair (i.e. tuple/list of length 2)')
return eval_data
[docs] def predict(self, X, num_batch=None, return_data=False, reset=True):
"""Run the prediction, always only use one device.
Parameters
----------
X : mxnet.DataIter
num_batch : int or None
The number of batch to run. Go though all batches if ``None``.
Returns
-------
y : numpy.ndarray or a list of numpy.ndarray if the network has multiple outputs.
The predicted value of the output.
"""
X = self._init_iter(X, None, is_train=False)
if reset:
X.reset()
data_shapes = X.provide_data
data_names = [x[0] for x in data_shapes]
type_dict = dict((key, value.dtype) for (key, value) in self.arg_params.items())
for x in X.provide_data:
if isinstance(x, DataDesc):
type_dict[x.name] = x.dtype
else:
type_dict[x[0]] = mx_real_t
self._init_predictor(data_shapes, type_dict)
batch_size = X.batch_size
data_arrays = [self._pred_exec.arg_dict[name] for name in data_names]
output_list = [[] for _ in range(len(self._pred_exec.outputs))]
if return_data:
data_list = [[] for _ in X.provide_data]
label_list = [[] for _ in X.provide_label]
i = 0
for batch in X:
_load_data(batch, data_arrays)
self._pred_exec.forward(is_train=False)
padded = batch.pad
real_size = batch_size - padded
for o_list, o_nd in zip(output_list, self._pred_exec.outputs):
o_list.append(o_nd[0:real_size].asnumpy())
if return_data:
for j, x in enumerate(batch.data):
data_list[j].append(x[0:real_size].asnumpy())
for j, x in enumerate(batch.label):
label_list[j].append(x[0:real_size].asnumpy())
i += 1
if num_batch is not None and i == num_batch:
break
outputs = [np.concatenate(x) for x in output_list]
if len(outputs) == 1:
outputs = outputs[0]
if return_data:
data = [np.concatenate(x) for x in data_list]
label = [np.concatenate(x) for x in label_list]
if len(data) == 1:
data = data[0]
if len(label) == 1:
label = label[0]
return outputs, data, label
else:
return outputs
[docs] def score(self, X, eval_metric='acc', num_batch=None, batch_end_callback=None, reset=True):
"""Run the model given an input and calculate the score
as assessed by an evaluation metric.
Parameters
----------
X : mxnet.DataIter
eval_metric : metric.metric
The metric for calculating score.
num_batch : int or None
The number of batches to run. Go though all batches if ``None``.
Returns
-------
s : float
The final score.
"""
# setup metric
if not isinstance(eval_metric, metric.EvalMetric):
eval_metric = metric.create(eval_metric)
X = self._init_iter(X, None, is_train=False)
if reset:
X.reset()
data_shapes = X.provide_data
data_names = [x[0] for x in data_shapes]
type_dict = dict((key, value.dtype) for (key, value) in self.arg_params.items())
for x in X.provide_data:
if isinstance(x, DataDesc):
type_dict[x.name] = x.dtype
else:
type_dict[x[0]] = mx_real_t
self._init_predictor(data_shapes, type_dict)
data_arrays = [self._pred_exec.arg_dict[name] for name in data_names]
for i, batch in enumerate(X):
if num_batch is not None and i == num_batch:
break
_load_data(batch, data_arrays)
self._pred_exec.forward(is_train=False)
eval_metric.update(batch.label, self._pred_exec.outputs)
if batch_end_callback is not None:
batch_end_params = BatchEndParam(epoch=0,
nbatch=i,
eval_metric=eval_metric,
locals=locals())
_multiple_callbacks(batch_end_callback, batch_end_params)
return eval_metric.get()[1]
[docs] def fit(self, X, y=None, eval_data=None, eval_metric='acc',
epoch_end_callback=None, batch_end_callback=None, kvstore='local', logger=None,
work_load_list=None, monitor=None, eval_end_callback=LogValidationMetricsCallback(),
eval_batch_end_callback=None):
"""Fit the model.
Parameters
----------
X : DataIter, or numpy.ndarray/NDArray
Training data. If `X` is a `DataIter`, the name or (if name not available)
the position of its outputs should match the corresponding variable
names defined in the symbolic graph.
y : numpy.ndarray/NDArray, optional
Training set label.
If X is ``numpy.ndarray`` or `NDArray`, `y` is required to be set.
While y can be 1D or 2D (with 2nd dimension as 1), its first dimension must be
the same as `X`, i.e. the number of data points and labels should be equal.
eval_data : DataIter or numpy.ndarray/list/NDArray pair
If eval_data is numpy.ndarray/list/NDArray pair,
it should be ``(valid_data, valid_label)``.
eval_metric : metric.EvalMetric or str or callable
The evaluation metric. This could be the name of evaluation metric
or a custom evaluation function that returns statistics
based on a minibatch.
epoch_end_callback : callable(epoch, symbol, arg_params, aux_states)
A callback that is invoked at end of each epoch.
This can be used to checkpoint model each epoch.
batch_end_callback: callable(epoch)
A callback that is invoked at end of each batch for purposes of printing.
kvstore: KVStore or str, optional
The KVStore or a string kvstore type: 'local', 'dist_sync', 'dist_async'
In default uses 'local', often no need to change for single machiine.
logger : logging logger, optional
When not specified, default logger will be used.
work_load_list : float or int, optional
The list of work load for different devices,
in the same order as `ctx`.
Note
----
KVStore behavior
- 'local', multi-devices on a single machine, will automatically choose best type.
- 'dist_sync', multiple machines communicating via BSP.
- 'dist_async', multiple machines with asynchronous communication.
"""
data = self._init_iter(X, y, is_train=True)
eval_data = self._init_eval_iter(eval_data)
if self.sym_gen:
self.symbol = self.sym_gen(data.default_bucket_key) # pylint: disable=no-member
self._check_arguments()
self.kwargs["sym"] = self.symbol
arg_names, param_names, aux_names = \
self._init_params(data.provide_data+data.provide_label)
# setup metric
if not isinstance(eval_metric, metric.EvalMetric):
eval_metric = metric.create(eval_metric)
# create kvstore
(kvstore, update_on_kvstore) = _create_kvstore(
kvstore, len(self.ctx), self.arg_params)
param_idx2name = {}
if update_on_kvstore:
param_idx2name.update(enumerate(param_names))
else:
for i, n in enumerate(param_names):
for k in range(len(self.ctx)):
param_idx2name[i*len(self.ctx)+k] = n
self.kwargs["param_idx2name"] = param_idx2name
# init optmizer
if isinstance(self.optimizer, str):
batch_size = data.batch_size
if kvstore and 'dist' in kvstore.type and '_async' not in kvstore.type:
batch_size *= kvstore.num_workers
optimizer = opt.create(self.optimizer,
rescale_grad=(1.0/batch_size),
**(self.kwargs))
elif isinstance(self.optimizer, opt.Optimizer):
if not optimizer.idx2name:
optimizer.idx2name = param_idx2name.copy()
optimizer = self.optimizer
# do training
_train_multi_device(self.symbol, self.ctx, arg_names, param_names, aux_names,
self.arg_params, self.aux_params,
begin_epoch=self.begin_epoch, end_epoch=self.num_epoch,
epoch_size=self.epoch_size,
optimizer=optimizer,
train_data=data, eval_data=eval_data,
eval_metric=eval_metric,
epoch_end_callback=epoch_end_callback,
batch_end_callback=batch_end_callback,
kvstore=kvstore, update_on_kvstore=update_on_kvstore,
logger=logger, work_load_list=work_load_list, monitor=monitor,
eval_end_callback=eval_end_callback,
eval_batch_end_callback=eval_batch_end_callback,
sym_gen=self.sym_gen)
[docs] def save(self, prefix, epoch=None, remove_amp_cast=True):
"""Checkpoint the model checkpoint into file.
You can also use `pickle` to do the job if you only work on Python.
The advantage of `load` and `save` (as compared to `pickle`) is that
the resulting file can be loaded from other MXNet language bindings.
One can also directly `load`/`save` from/to cloud storage(S3, HDFS)
Parameters
----------
prefix : str
Prefix of model name.
remove_amp_cast : bool, optional
Whether to remove the amp_cast and amp_multicast operators, before saving the model.
Notes
-----
- ``prefix-symbol.json`` will be saved for symbol.
- ``prefix-epoch.params`` will be saved for parameters.
"""
if epoch is None:
epoch = self.num_epoch
assert epoch is not None
save_checkpoint(prefix, epoch, self.symbol, self.arg_params, self.aux_params, remove_amp_cast=remove_amp_cast)
[docs] @staticmethod
def load(prefix, epoch, ctx=None, **kwargs):
"""Load model checkpoint from file.
Parameters
----------
prefix : str
Prefix of model name.
epoch : int
epoch number of model we would like to load.
ctx : Context or list of Context, optional
The device context of training and prediction.
kwargs : dict
Other parameters for model, including `num_epoch`, optimizer and `numpy_batch_size`.
Returns
-------
model : FeedForward
The loaded model that can be used for prediction.
Notes
-----
- ``prefix-symbol.json`` will be saved for symbol.
- ``prefix-epoch.params`` will be saved for parameters.
"""
symbol, arg_params, aux_params = load_checkpoint(prefix, epoch)
return FeedForward(symbol, ctx=ctx,
arg_params=arg_params, aux_params=aux_params,
begin_epoch=epoch,
**kwargs)
[docs] @staticmethod
def create(symbol, X, y=None, ctx=None,
num_epoch=None, epoch_size=None, optimizer='sgd', initializer=Uniform(0.01),
eval_data=None, eval_metric='acc',
epoch_end_callback=None, batch_end_callback=None,
kvstore='local', logger=None, work_load_list=None,
eval_end_callback=LogValidationMetricsCallback(),
eval_batch_end_callback=None, **kwargs):
"""Functional style to create a model.
This function is more consistent with functional
languages such as R, where mutation is not allowed.
Parameters
----------
symbol : Symbol
The symbol configuration of a computation network.
X : DataIter
Training data.
y : numpy.ndarray, optional
If `X` is a ``numpy.ndarray``, `y` must be set.
ctx : Context or list of Context, optional
The device context of training and prediction.
To use multi-GPU training, pass in a list of GPU contexts.
num_epoch : int, optional
The number of training epochs(epochs).
epoch_size : int, optional
Number of batches in a epoch. In default, it is set to
``ceil(num_train_examples / batch_size)``.
optimizer : str or Optimizer, optional
The name of the chosen optimizer, or an optimizer object, used for training.
initializer : initializer function, optional
The initialization scheme used.
eval_data : DataIter or numpy.ndarray pair
If `eval_set` is ``numpy.ndarray`` pair, it should
be (`valid_data`, `valid_label`).
eval_metric : metric.EvalMetric or str or callable
The evaluation metric. Can be the name of an evaluation metric
or a custom evaluation function that returns statistics
based on a minibatch.
epoch_end_callback : callable(epoch, symbol, arg_params, aux_states)
A callback that is invoked at end of each epoch.
This can be used to checkpoint model each epoch.
batch_end_callback: callable(epoch)
A callback that is invoked at end of each batch for print purposes.
kvstore: KVStore or str, optional
The KVStore or a string kvstore type: 'local', 'dist_sync', 'dis_async'.
Defaults to 'local', often no need to change for single machine.
logger : logging logger, optional
When not specified, default logger will be used.
work_load_list : list of float or int, optional
The list of work load for different devices,
in the same order as `ctx`.
"""
model = FeedForward(symbol, ctx=ctx, num_epoch=num_epoch,
epoch_size=epoch_size,
optimizer=optimizer, initializer=initializer, **kwargs)
model.fit(X, y, eval_data=eval_data, eval_metric=eval_metric,
epoch_end_callback=epoch_end_callback,
batch_end_callback=batch_end_callback,
kvstore=kvstore,
logger=logger,
work_load_list=work_load_list,
eval_end_callback=eval_end_callback,
eval_batch_end_callback=eval_batch_end_callback)
return model
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