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Paddle/python/paddle/v2/inference.py

105 lines
3.9 KiB

import numpy
import py_paddle.swig_paddle as api
import collections
import topology
import minibatch
from data_feeder import DataFeeder
__all__ = ['infer']
class Inference(object):
def __init__(self, output_layer, parameters):
topo = topology.Topology(output_layer)
gm = api.GradientMachine.createFromConfigProto(
topo.proto(), api.CREATE_MODE_TESTING, [api.PARAMETER_VALUE])
for param in gm.getParameters():
val = param.getBuf(api.PARAMETER_VALUE)
name = param.getName()
assert isinstance(val, api.Vector)
val.copyFromNumpyArray(parameters.get(name).flatten())
self.__gradient_machine__ = gm
self.__data_types__ = topo.data_type()
def iter_infer(self, input=None, batch_size=None, reader=None,
feeding=None):
if reader is None:
assert input is not None and isinstance(input, collections.Iterable)
if not isinstance(input, collections.Iterable):
raise TypeError("When reader is None, input should be whole "
"inference data and should be iterable")
if batch_size is None:
if not hasattr(input, '__len__'):
raise ValueError("Should set batch size when input data "
"don't contain length.")
batch_size = len(input)
def __reader_impl__():
for each_sample in input:
yield each_sample
reader = minibatch.batch(__reader_impl__, batch_size=batch_size)
else:
if input is not None:
raise ValueError("User should set either input or reader, "
"should not set them both.")
feeder = DataFeeder(self.__data_types__, feeding)
self.__gradient_machine__.start()
for data_batch in reader():
yield self.__gradient_machine__.forwardTest(feeder(data_batch))
self.__gradient_machine__.finish()
def iter_infer_field(self, field, **kwargs):
for result in self.iter_infer(**kwargs):
yield [each_result[field] for each_result in result]
def infer(self, field='value', **kwargs):
retv = None
for result in self.iter_infer_field(field=field, **kwargs):
if retv is None:
retv = [[]] * len(result)
for i, item in enumerate(result):
retv[i].append(item)
retv = [numpy.concatenate(out) for out in retv]
if len(retv) == 1:
return retv[0]
else:
return retv
def infer(output_layer, parameters, input=None, feeding=None, field='value'):
"""
Infer a neural network by given neural network output and parameters. The
user should pass either a batch of input data or reader method.
Example usages:
.. code-block:: python
result = paddle.infer(prediction, parameters, input=SomeData,
batch_size=32)
print result
:param output_layer: output of the neural network that would be inferred
:type output_layer: paddle.v2.config_base.Layer
:param parameters: parameters of the neural network.
:type parameters: paddle.v2.parameters.Parameters
:param input: input data batch. Should be a python iterable object, and each
element is the data batch.
:type input: collections.Iterable
:param feeding: Reader dictionary. Default could generate from input
value.
:param field: The prediction field. It should in [`value`, `ids`]. `value`
means return the prediction probabilities, `ids` means return
the prediction labels. Default is `value`
:type field: str
:return: a numpy array
:rtype: numpy.ndarray
"""
inferer = Inference(output_layer=output_layer, parameters=parameters)
return inferer.infer(field=field, input=input, feeding=feeding)