提交 af235f4e authored 作者: Iban Harlouchet's avatar Iban Harlouchet 提交者: Arnaud Bergeron

testcode for doc/tutorial/aliasing.txt

上级 cf7c0629
...@@ -59,26 +59,33 @@ A ``borrow`` argument can be provided to the shared-variable constructor. ...@@ -59,26 +59,33 @@ A ``borrow`` argument can be provided to the shared-variable constructor.
.. If you modify this code, also change : .. If you modify this code, also change :
.. theano/tests/test_tutorial.py:T_aliasing.test_aliasing_1 .. theano/tests/test_tutorial.py:T_aliasing.test_aliasing_1
.. code-block:: python .. testcode:: borrow
import numpy, theano import numpy, theano
np_array = numpy.ones(2, dtype='float32') np_array = numpy.ones(2, dtype='float32')
s_default = theano.shared(np_array) s_default = theano.shared(np_array)
s_false = theano.shared(np_array, borrow=False) s_false = theano.shared(np_array, borrow=False)
s_true = theano.shared(np_array, borrow=True) s_true = theano.shared(np_array, borrow=True)
By default (*s_default*) and when explicitly setting ``borrow=False``, the By default (*s_default*) and when explicitly setting ``borrow=False``, the
shared variable we construct gets a [deep] copy of *np_array*. So changes we shared variable we construct gets a [deep] copy of *np_array*. So changes we
subsequently make to *np_array* have no effect on our shared variable. subsequently make to *np_array* have no effect on our shared variable.
.. code-block:: python .. testcode:: borrow
np_array += 1 # now it is an array of 2.0 s np_array += 1 # now it is an array of 2.0 s
print(s_default.get_value())
print(s_false.get_value())
print(s_true.get_value())
.. testoutput:: borrow
[ 1. 1.]
[ 1. 1.]
[ 2. 2.]
s_default.get_value() # -> array([1.0, 1.0])
s_false.get_value() # -> array([1.0, 1.0])
s_true.get_value() # -> array([2.0, 2.0])
If we are running this with the CPU as the device, If we are running this with the CPU as the device,
then changes we make to *np_array* *right away* will show up in then changes we make to *np_array* *right away* will show up in
...@@ -120,12 +127,12 @@ retrieved. ...@@ -120,12 +127,12 @@ retrieved.
.. If you modify this code, also change : .. If you modify this code, also change :
.. theano/tests/test_tutorial.py:T_aliasing.test_aliasing_2 .. theano/tests/test_tutorial.py:T_aliasing.test_aliasing_2
.. code-block:: python .. testcode:: borrow
s = theano.shared(np_array) s = theano.shared(np_array)
v_false = s.get_value(borrow=False) # N.B. borrow default is False v_false = s.get_value(borrow=False) # N.B. borrow default is False
v_true = s.get_value(borrow=True) v_true = s.get_value(borrow=True)
When ``borrow=False`` is passed to ``get_value``, it means that the return value When ``borrow=False`` is passed to ``get_value``, it means that the return value
...@@ -146,7 +153,7 @@ then you should use the ``return_internal_type=True`` argument to ...@@ -146,7 +153,7 @@ then you should use the ``return_internal_type=True`` argument to
constant time), but might return various datatypes depending on contextual constant time), but might return various datatypes depending on contextual
factors (e.g. the compute device, the dtype of the NumPy array). factors (e.g. the compute device, the dtype of the NumPy array).
.. code-block:: python .. testcode:: borrow
v_internal = s.get_value(borrow=True, return_internal_type=True) v_internal = s.get_value(borrow=True, return_internal_type=True)
...@@ -178,7 +185,7 @@ that Theano *may* reuse the buffer you provide as the internal storage for the v ...@@ -178,7 +185,7 @@ that Theano *may* reuse the buffer you provide as the internal storage for the v
A standard pattern for manually updating the value of a ``shared`` variable is as A standard pattern for manually updating the value of a ``shared`` variable is as
follows: follows:
.. code-block:: python .. testcode:: borrow
s.set_value( s.set_value(
some_inplace_fn(s.get_value(borrow=True)), some_inplace_fn(s.get_value(borrow=True)),
...@@ -227,7 +234,7 @@ that control how ``theano.function`` handles its argument[s] and return value[s] ...@@ -227,7 +234,7 @@ that control how ``theano.function`` handles its argument[s] and return value[s]
.. If you modify this code, also change : .. If you modify this code, also change :
.. theano/tests/test_tutorial.py:T_aliasing.test_aliasing_3 .. theano/tests/test_tutorial.py:T_aliasing.test_aliasing_3
.. code-block:: python .. testcode::
import theano, theano.tensor import theano, theano.tensor
...@@ -261,42 +268,42 @@ graph. ...@@ -261,42 +268,42 @@ graph.
For GPU graphs, this borrowing can have a major speed impact. See the following code: For GPU graphs, this borrowing can have a major speed impact. See the following code:
.. code-block:: python .. testcode::
from theano import function, config, shared, sandbox, tensor, Out from theano import function, config, shared, sandbox, tensor, Out
import numpy import numpy
import time import time
vlen = 10 * 30 * 768 # 10 x # cores x # threads per core vlen = 10 * 30 * 768 # 10 x # cores x # threads per core
iters = 1000 iters = 1000
rng = numpy.random.RandomState(22) rng = numpy.random.RandomState(22)
x = shared(numpy.asarray(rng.rand(vlen), config.floatX)) x = shared(numpy.asarray(rng.rand(vlen), config.floatX))
f1 = function([], sandbox.cuda.basic_ops.gpu_from_host(tensor.exp(x))) f1 = function([], sandbox.cuda.basic_ops.gpu_from_host(tensor.exp(x)))
f2 = function([], f2 = function([],
Out(sandbox.cuda.basic_ops.gpu_from_host(tensor.exp(x)), Out(sandbox.cuda.basic_ops.gpu_from_host(tensor.exp(x)),
borrow=True)) borrow=True))
t0 = time.time() t0 = time.time()
for i in xrange(iters): for i in xrange(iters):
r = f1() r = f1()
t1 = time.time() t1 = time.time()
no_borrow = t1 - t0 no_borrow = t1 - t0
t0 = time.time() t0 = time.time()
for i in xrange(iters): for i in xrange(iters):
r = f2() r = f2()
t1 = time.time() t1 = time.time()
print 'Looping', iters, 'times took', no_borrow, 'seconds without borrow', print 'Looping', iters, 'times took', no_borrow, 'seconds without borrow',
print 'and', t1 - t0, 'seconds with borrow.' print 'and', t1 - t0, 'seconds with borrow.'
if numpy.any([isinstance(x.op, tensor.Elemwise) and if numpy.any([isinstance(x.op, tensor.Elemwise) and
('Gpu' not in type(x.op).__name__) ('Gpu' not in type(x.op).__name__)
for x in f1.maker.fgraph.toposort()]): for x in f1.maker.fgraph.toposort()]):
print 'Used the cpu' print 'Used the cpu'
else: else:
print 'Used the gpu' print 'Used the gpu'
Which produces this output: Which produces this output:
.. code-block:: text .. code-block:: none
$ THEANO_FLAGS=device=gpu0,floatX=float32 python test1.py $ THEANO_FLAGS=device=gpu0,floatX=float32 python test1.py
Using gpu device 0: GeForce GTX 275 Using gpu device 0: GeForce GTX 275
......
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