提交 0a889321 authored 作者: slefrancois's avatar slefrancois

final fft ops take shape as input, interface passes input array shape + odd correction

上级 29271d0a
......@@ -38,7 +38,14 @@ class CuRFFTOp(Op):
broadcastable=[False] * (inp.type.ndim + 1),
context_name=inp.type.context_name)
def make_node(self, inp):
def make_node(self, inp, s=None):
# A shape parameter s can be provided as an input. For now this is used to
# manage odd transform sizes.
# Later this could be extended to handle padding and trunkation,
# following numpy's interface. However, cuFFT expects array that match
# the shape given to the plan, so padding will have to be done in the op.
# The effect of padding on gradients has yet to be investigated.
if not scikits_cuda_available:
raise RuntimeError("scikits.cuda is needed for CuFFTOp")
......@@ -52,9 +59,16 @@ class CuRFFTOp(Op):
basic_ops.as_gpuarray_variable(inp,
basic_ops.infer_context_name(inp)))
# If no shape is provided as input, default to input data shape.
if s is None:
s = inp.shape[1:]
s = T.as_tensor_variable(s)
assert inp.dtype == "float32"
assert s.ndim == 1
assert 'int' in s.dtype
return theano.Apply(self, [inp], [self.output_type(inp)()])
return theano.Apply(self, [inp, s], [self.output_type(inp)()])
def make_thunk(self, node, storage_map, _, _2):
......@@ -70,9 +84,13 @@ class CuRFFTOp(Op):
def thunk():
input_shape = inputs[0][0].shape
s = inputs[1][0]
# Since padding is not supported, assert s matches input shape.
assert (input_shape[1:] == s).all()
# construct output shape
output_shape = list(input_shape)
output_shape = [input_shape[0]] + list(s)
# DFT of real input is symmetric, no need to store
# redundant coefficients
output_shape[-1] = output_shape[-1] // 2 + 1
......@@ -99,13 +117,15 @@ class CuRFFTOp(Op):
# only initialise plan if necessary
if plan[0] is None or plan_input_shape[0] != input_shape:
plan_input_shape[0] = input_shape
plan[0] = fft.Plan(input_shape[1:], np.float32, np.complex64,
plan[0] = fft.Plan(s, np.float32, np.complex64,
batch=input_shape[0])
# Sync GPU variables before computation
input_pycuda.sync()
output_pycuda.sync()
fft.fft(input_pycuda, output_pycuda, plan[0])
# Sync results to ensure output contains completed computation
pycuda.driver.Context.synchronize()
......@@ -117,15 +137,18 @@ class CuRFFTOp(Op):
def grad(self, inputs, output_grads):
gout, = output_grads
s = inputs[0].shape[1:]
is_odd = s[-1] % 2
# Divide the last dimension of the output gradients by 2, they are
s = inputs[1]
# Divide the last dimension of the output gradients by 2, they are
# double-counted by the real-IFFT due to symmetry, except the first
# and last elements (for even transforms) which are unique.
idx = [slice(None)] * (gout.ndim - 2) \
+ [slice(1, (s[-1] // 2) + is_odd)] + [slice(None)]
gout = T.set_subtensor(gout[idx], gout[idx]*0.5)
return [cuirfft_op(gout, is_odd)]
+ [slice(1, (s[-1] // 2) + (s[-1] % 2))] + [slice(None)]
gout = T.set_subtensor(gout[idx], gout[idx] * 0.5)
return [cuirfft_op(gout, s), DisconnectedType()()]
def connection_pattern(self, node):
# Specificy that shape input parameter has no connection to graph and gradients.
return [[True], [False]]
curfft_op = CuRFFTOp()
......@@ -135,12 +158,19 @@ class CuIRFFTOp(Op):
__props__ = ()
def output_type(self, inp):
# add one extra dim for real/imag
# remove extra dim for real/imag
return GpuArrayType(inp.dtype,
broadcastable=[False] * (inp.type.ndim - 1),
context_name=inp.type.context_name)
def make_node(self, inp, is_odd):
def make_node(self, inp, s=None):
# A shape parameter is expected as an input. For now this is used to
# manage odd transform sizes.
# Later this could be extended to handle padding and trunkation,
# following numpy's interface. However, cuFFT expects array that match
# the shape given to the plan, so padding will have to be done in the op.
# The effect of padding on gradients has yet to be investigated.
if not scikits_cuda_available:
raise RuntimeError("scikits.cuda is needed for CuIFFTOp")
......@@ -153,12 +183,17 @@ class CuIRFFTOp(Op):
inp = basic_ops.gpu_contiguous(
basic_ops.as_gpuarray_variable(inp,
basic_ops.infer_context_name(inp)))
is_odd = T.as_tensor_variable(is_odd)
# If no shape is provided as input, calculate shape assuming even real transform.
if s is None:
s = inp.shape[1:-1]
s = T.set_subtensor(s[-1], (s[-1] - 1) * 2)
s = T.as_tensor_variable(s)
assert inp.dtype == "float32"
assert 'int' in is_odd.dtype
assert s.ndim == 1
return theano.Apply(self, [inp, is_odd], [self.output_type(inp)()])
return theano.Apply(self, [inp, s], [self.output_type(inp)()])
def make_thunk(self, node, storage_map, _, _2):
......@@ -174,16 +209,18 @@ class CuIRFFTOp(Op):
def thunk():
input_shape = inputs[0][0].shape
is_odd = inputs[1][0]
assert is_odd in (0, 1)
s = inputs[1][0]
# Since padding is not supported, assert that last dimension corresponds to
# input forward transform size.
assert (input_shape[1:-2] == s[:-1]).all()
assert ((input_shape[-2] - 1) * 2 + s[-1] % 2 == s[-1]).all()
# construct output shape
# chop off the extra length-2 dimension for real/imag
output_shape = list(input_shape[:-1])
# restore full signal length
output_shape[-1] = (output_shape[-1] - 1) * 2 + is_odd
output_shape = [input_shape[0]] + list(s)
output_shape = tuple(output_shape)
z = outputs[0]
# only allocate if there is no previous allocation of the
......@@ -202,8 +239,9 @@ class CuIRFFTOp(Op):
# only initialise plan if necessary
if plan[0] is None or plan_input_shape[0] != input_shape:
plan_input_shape[0] = input_shape
plan[0] = fft.Plan(output_shape[1:], np.complex64, np.float32,
plan[0] = fft.Plan(s, np.complex64, np.float32,
batch=output_shape[0])
# Sync GPU variables before computation
input_pycuda.sync()
output_pycuda.sync()
......@@ -221,33 +259,35 @@ class CuIRFFTOp(Op):
thunk.lazy = False
return thunk
def grad(self, inputs, output_grads):
gout, = output_grads
s = gout.shape
gf = curfft_op(gout)
s = inputs[1]
gf = curfft_op(gout, s)
# Multiply the last dimension of the gradient by 2, they represent
# both positive and negative frequencies, except the first
# and last elements (for even transforms) which are unique.
idx = [slice(None)] * (gf.ndim - 2) \
+ [slice(1, (s[-1] // 2) + (s[-1] % 2))] + [slice(None)]
gf = T.set_subtensor(gf[idx], gf[idx]*2)
+ [slice(1, (s[-1] // 2) + (s[-1] % 2))] + [slice(None)]
gf = T.set_subtensor(gf[idx], gf[idx] * 2)
return [gf, DisconnectedType()()]
def connection_pattern(self, node):
return [[True],[False]]
# Specificy that shape input parameter has no connection to graph and gradients.
return [[True], [False]]
cuirfft_op = CuIRFFTOp()
def curfft(inp, norm=None):
"""
Performs the fast Fourier transform of a real-valued output on the GPU
Performs the fast Fourier transform of a real-valued output on the GPU
through the gpuarray backend.
The input must be a real-valued float32 variable of dimensions (m, ..., n).
It performs FFTs of size (..., n) on m batches.
The output is a GpuArray of dimensions (m, ..., n//2+1, 2). The second to
The output is a GpuArray of dimensions (m, ..., n//2+1, 2). The second to
last dimension of the output contains the n//2+1 non-trivial elements of
the real-valued FFTs. The real and imaginary parts are stored as two
float32 arrays, emulating complex64. Since theano does not support complex
......@@ -269,14 +309,14 @@ def curfft(inp, norm=None):
s = inp.shape[1:]
cond_norm = _unitary(norm)
if cond_norm is None or cond_norm == "no_norm":
scaling = 1
elif cond_norm == "ortho":
scaling = 1
if cond_norm == "ortho":
scaling = T.sqrt(s.prod().astype('float32'))
return curfft_op(inp) / scaling
def cuirfft(inp, norm=None, is_odd=0):
return curfft_op(inp, s) / scaling
def cuirfft(inp, norm=None, is_odd=False):
"""
Performs the real-valued output inverse Fourier Transform using the
gpuarray backend.
......@@ -288,37 +328,42 @@ def cuirfft(inp, norm=None, is_odd=0):
given that Theano does not support complex numbers.
The output is a real-valued float32 variable of dimensions (m, ..., n)
giving the m inverse FFTs.
giving the m inverse FFTs.
Parameters
----------
inp
Array of float32 of size (m, ..., n//2+1, 2), containing m inputs
with n/2+1 non-trivial elements on the last dimension and real
Array of float32 of size (m, ..., n//2+1, 2), containing m inputs
with n//2+1 non-trivial elements on the last dimension and real
and imaginary parts stored as separate arrays.
norm : {None, 'ortho', 'no_norm'}
Normalization of transform. Following numpy, default *None* normalizes
only the inverse transform by n, 'ortho' yields the unitary transform
(:math:`1/\sqrt n` forward and inverse). In addition, 'no_norm' leaves
the transform unnormalized.
is_odd : {True, False}
Set to True to get a real inverse transform output with an odd last dimension
of length (N-1)*2 + 1 for an input last dimension of length N.
"""
if is_odd != 0:
is_odd = 1
if is_odd not in (True, False):
raise ValueError("Invalid value %s for id_odd, must be True or False" % is_odd)
s = inp.shape[1:-1]
s = T.set_subtensor(s[-1], (s[-1] - 1) * 2 + is_odd)
if is_odd:
s = T.set_subtensor(s[-1], (s[-1] - 1) * 2 + 1)
else:
s = T.set_subtensor(s[-1], (s[-1] - 1) * 2)
cond_norm = _unitary(norm)
scaling = 1
if cond_norm is None:
scaling = s.prod().astype('float32')
if cond_norm == "ortho":
elif cond_norm == "ortho":
scaling = T.sqrt(s.prod().astype('float32'))
if cond_norm == "no_norm":
scaling = 1
return cuirfft_op(inp, is_odd) / scaling
return cuirfft_op(inp, s) / scaling
def _unitary(norm):
if norm not in (None, "ortho", "no_norm"):
......
......@@ -25,14 +25,13 @@ if not pycuda_available: # noqa
import theano.gpuarray.cuda_fft
# Transform sizes
N = 16
N = 64
class TestFFT(unittest.TestCase):
def test_1Dfft(self):
inputs_val = np.random.random((1, N)).astype('float32')
inputs = theano.shared(inputs_val)
x = T.matrix('x', dtype='float32')
rfft = theano.gpuarray.fft.curfft(x)
......@@ -40,200 +39,215 @@ class TestFFT(unittest.TestCase):
res_rfft = f_rfft(inputs_val)
res_rfft_comp = (np.asarray(res_rfft[:, :, 0]) +
1j * np.asarray(res_rfft[:, :, 1]))
rfft_ref = numpy.fft.rfft(inputs_val, axis=1)
utt.assert_allclose(rfft_ref, res_rfft_comp)
utt.assert_allclose(rfft_ref, res_rfft_comp)
m = rfft.type()
irfft = theano.gpuarray.fft.cuirfft(m)
f_irfft = theano.function([m], irfft, mode=mode_with_gpu)
res_irfft = f_irfft(res_rfft)
utt.assert_allclose(inputs_val, np.asarray(res_irfft))
# The numerical gradient of the FFT is sensitive, must set large
# enough epsilon to get good accuracy.
eps = 1e-1
def f_rfft(inp):
return theano.gpuarray.fft.curfft(inp)
inputs_val = np.random.random((1, N)).astype('float32')
utt.verify_grad(f_rfft, [inputs_val], eps=eps)
def f_irfft(inp):
return theano.gpuarray.fft.cuirfft(inp)
inputs_val = np.random.random((1, N//2+1, 2)).astype('float32')
inputs_val = np.random.random((1, N // 2 + 1, 2)).astype('float32')
utt.verify_grad(f_irfft, [inputs_val], eps=eps)
def test_rfft(self):
inputs_val = np.random.random((1, N, N)).astype('float32')
inputs = theano.shared(inputs_val)
rfft = theano.gpuarray.fft.curfft(inputs)
f_rfft = theano.function([], rfft, mode=mode_with_gpu)
res_rfft = f_rfft()
res_rfft_comp = (np.asarray(res_rfft[:, :, :, 0]) +
1j * np.asarray(res_rfft[:, :, :, 1]))
rfft_ref = numpy.fft.rfftn(inputs_val, axes=(1,2))
rfft_ref = numpy.fft.rfftn(inputs_val, axes=(1, 2))
utt.assert_allclose(rfft_ref, res_rfft_comp, atol=1e-4, rtol=1e-4)
def test_irfft(self):
inputs_val = np.random.random((1, N, N)).astype('float32')
inputs = theano.shared(inputs_val)
fft = theano.gpuarray.fft.curfft(inputs)
f_fft = theano.function([], fft, mode=mode_with_gpu)
res_fft = f_fft()
m = fft.type()
ifft = theano.gpuarray.fft.cuirfft(m)
f_ifft = theano.function([m], ifft, mode=mode_with_gpu)
res_ifft = f_ifft(res_fft)
utt.assert_allclose(inputs_val, np.asarray(res_ifft))
def test_type(self):
inputs_val = np.random.random((1, N)).astype('float64')
inputs = theano.shared(inputs_val)
with self.assertRaises(AssertionError):
theano.gpuarray.fft.curfft(inputs)
with self.assertRaises(AssertionError):
theano.gpuarray.fft.cuirfft(inputs)
def test_norm(self):
inputs_val = np.random.random((1, N, N)).astype('float32')
inputs = theano.shared(inputs_val)
# Unitary normalization
rfft = theano.gpuarray.fft.curfft(inputs, norm='ortho')
f_rfft = theano.function([], rfft, mode=mode_with_gpu)
res_rfft = f_rfft()
res_rfft_comp = (np.asarray(res_rfft[:, :, :, 0]) +
1j * np.asarray(res_rfft[:, :, :, 1]))
rfft_ref_ortho = numpy.fft.rfftn(inputs_val, axes=(1,2), norm='ortho')
rfft_ref_ortho = numpy.fft.rfftn(inputs_val, axes=(1, 2), norm='ortho')
utt.assert_allclose(rfft_ref_ortho, res_rfft_comp,
atol=1e-4, rtol=1e-4)
atol=1e-4, rtol=1e-4)
# No normalization
rfft = theano.gpuarray.fft.curfft(inputs, norm='no_norm')
f_rfft = theano.function([], rfft, mode=mode_with_gpu)
res_rfft = f_rfft()
res_rfft_comp = (np.asarray(res_rfft[:, :, :, 0]) +
1j * np.asarray(res_rfft[:, :, :, 1]))
utt.assert_allclose(rfft_ref_ortho * np.sqrt(N*N),
res_rfft_comp, atol=1e-4, rtol=1e-4)
utt.assert_allclose(rfft_ref_ortho * np.sqrt(N * N),
res_rfft_comp, atol=1e-4, rtol=1e-4)
# Inverse FFT inputs
inputs_val = np.random.random((1, N, N // 2 + 1, 2)).astype('float32')
inputs = theano.shared(inputs_val)
inputs_ref = inputs_val[:, :, :, 0] + 1j * inputs_val[:, :, :, 1]
# Unitary normalization inverse FFT
irfft = theano.gpuarray.fft.cuirfft(inputs, norm='ortho')
f_irfft = theano.function([], irfft, mode=mode_with_gpu)
res_irfft = f_irfft()
irfft_ref_ortho = numpy.fft.irfftn(inputs_ref, axes=(1,2), norm='ortho')
irfft_ref_ortho = numpy.fft.irfftn(
inputs_ref, axes=(1, 2), norm='ortho')
utt.assert_allclose(irfft_ref_ortho,
res_irfft, atol=1e-4, rtol=1e-4)
res_irfft, atol=1e-4, rtol=1e-4)
# No normalization inverse FFT
irfft = theano.gpuarray.fft.cuirfft(inputs, norm='no_norm')
f_irfft = theano.function([], irfft, mode=mode_with_gpu)
res_irfft = f_irfft()
utt.assert_allclose(irfft_ref_ortho * np.sqrt(N*N),
res_irfft, atol=1e-4, rtol=1e-4)
utt.assert_allclose(irfft_ref_ortho * np.sqrt(N * N),
res_irfft, atol=1e-4, rtol=1e-4)
def test_grad(self):
# The numerical gradient of the FFT is sensitive, must set large
# enough epsilon to get good accuracy.
eps = 1e-1
def f_rfft(inp):
return theano.gpuarray.fft.curfft(inp)
inputs_val = np.random.random((1, N, N)).astype('float32')
utt.verify_grad(f_rfft, [inputs_val], eps=eps)
def f_irfft(inp):
return theano.gpuarray.fft.cuirfft(inp)
inputs_val = np.random.random((1, N, N // 2 + 1, 2)).astype('float32')
utt.verify_grad(f_irfft, [inputs_val], eps=eps)
def f_rfft(inp):
return theano.gpuarray.fft.curfft(inp, norm='ortho')
inputs_val = np.random.random((1, N, N)).astype('float32')
utt.verify_grad(f_rfft, [inputs_val], eps=eps)
def f_irfft(inp):
return theano.gpuarray.fft.cuirfft(inp, norm='no_norm')
inputs_val = np.random.random((1, N, N // 2 + 1, 2)).astype('float32')
utt.verify_grad(f_irfft, [inputs_val], eps=eps)
def test_odd(self):
M = N - 1
inputs_val = np.random.random((1, M, M)).astype('float32')
inputs = theano.shared(inputs_val)
rfft = theano.gpuarray.fft.curfft(inputs)
f_rfft = theano.function([], rfft, mode=mode_with_gpu)
res_rfft = f_rfft()
res_rfft_comp = (np.asarray(res_rfft[:, :, :, 0]) +
1j * np.asarray(res_rfft[:, :, :, 1]))
rfft_ref = numpy.fft.rfftn(inputs_val, s=(M,M), axes=(1,2))#, s=(M, M), axes=(1,2))
utt.assert_allclose(rfft_ref, res_rfft_comp, atol=1e-4, rtol=1e-4)
rfft_ref = numpy.fft.rfftn(inputs_val, s=(M, M), axes=(1, 2))
utt.assert_allclose(rfft_ref, res_rfft_comp, atol=1e-4, rtol=1e-4)
m = rfft.type()
ifft = theano.gpuarray.fft.cuirfft(m, is_odd=True)
f_ifft = theano.function([m], ifft, mode=mode_with_gpu)
res_ifft = f_ifft(res_rfft)
utt.assert_allclose(inputs_val, np.asarray(res_ifft))
inputs_val = np.random.random((1, M, M//2+1, 2)).astype('float32')
inputs_val = np.random.random((1, M, M // 2 + 1, 2)).astype('float32')
inputs = theano.shared(inputs_val)
irfft = theano.gpuarray.fft.cuirfft(inputs, norm='ortho', is_odd=True)
f_irfft = theano.function([], irfft, mode=mode_with_gpu)
res_irfft = f_irfft()
inputs_ref = inputs_val[:, :, :, 0] + 1j * inputs_val[:, :, :, 1]
irfft_ref = numpy.fft.irfftn(inputs_ref, s=(M, M), axes=(1,2), norm='ortho')
irfft_ref = numpy.fft.irfftn(
inputs_ref, s=(M, M), axes=(1, 2), norm='ortho')
utt.assert_allclose(irfft_ref, res_irfft, atol=1e-4, rtol=1e-4)
# The numerical gradient of the FFT is sensitive, must set large
# enough epsilon to get good accuracy.
eps = 1e-1
def f_rfft(inp):
return theano.gpuarray.fft.curfft(inp)
inputs_val = np.random.random((1, M, M)).astype('float32')
utt.verify_grad(f_rfft, [inputs_val], eps=eps)
def f_irfft(inp):
return theano.gpuarray.fft.cuirfft(inp, is_odd=True)
inputs_val = np.random.random((1, M, M // 2 + 1, 2)).astype('float32')
utt.verify_grad(f_irfft, [inputs_val], eps=eps)
def f_rfft(inp):
return theano.gpuarray.fft.curfft(inp, norm='ortho')
inputs_val = np.random.random((1, M, M)).astype('float32')
utt.verify_grad(f_rfft, [inputs_val], eps=eps)
def f_irfft(inp):
return theano.gpuarray.fft.cuirfft(inp, norm='no_norm', is_odd=True)
inputs_val = np.random.random((1, M, M // 2 + 1, 2)).astype('float32')
utt.verify_grad(f_irfft, [inputs_val], eps=eps)
def test_params(self):
inputs_val = np.random.random((1, N)).astype('float32')
inputs = theano.shared(inputs_val)
with self.assertRaises(ValueError):
theano.gpuarray.fft.curfft(inputs, norm=123)
inputs_val = np.random.random((1, N // 2 + 1, 2)).astype('float32')
inputs = theano.shared(inputs_val)
with self.assertRaises(ValueError):
theano.gpuarray.fft.cuirfft(inputs, norm=123)
with self.assertRaises(ValueError):
theano.gpuarray.fft.cuirfft(inputs, is_odd=123)
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