提交 2e417b60 编写于 作者: Z zchen0211

batch norm

上级 6c0b3836
......@@ -6,8 +6,26 @@ from paddle.v2.framework.op import Operator
def _reference_training(x, scale, offset, epsilon, data_format):
if data_format != "NHWC":
raise ValueError("data_format must be NHWC, got %s." % data_format)
if data_format == "NCHW":
n, c, h, w = x.shape
x_square = x * x
x_square_sum = np.sum(x_square, (0, 2, 3))
x_sum = np.sum(x, axis=(0, 2, 3))
element_count = np.size(x) / int(np.shape(x)[1])
mean = x_sum / element_count
var = x_square_sum / element_count - mean * mean
mean_tile = np.reshape(mean, (1, c, 1, 1))
mean_tile = np.tile(mean_tile, (n, 1, h, w))
var_tile = np.reshape(var, (1, c, 1, 1))
var_tile = np.tile(var_tile, (n, 1, h, w))
normalized = (x - mean_tile) / np.sqrt(var_tile + epsilon)
scale_tile = np.reshape(scale, (1, c, 1, 1))
scale_tile = np.tile(scale_tile, (n, 1, h, w))
offset_tile = np.reshape(offset, (1, c, 1, 1))
offset_tile = np.reshape(offset_tile, (1, c, 1, 1))
y = normalized * scale_tile + offset_tile
return y, mean, var
elif data_format == "NHWC":
x_square = x * x
x_square_sum = np.sum(x_square, (0, 1, 2))
x_sum = np.sum(x, axis=(0, 1, 2))
......@@ -16,6 +34,8 @@ def _reference_training(x, scale, offset, epsilon, data_format):
var = x_square_sum / element_count - mean * mean
normalized = (x - mean) / np.sqrt(var + epsilon)
return (normalized * scale + offset), mean, var
else:
raise ValueError("Unknown data order.")
def _reference_grad(x, grad_y, scale, mean, var, epsilon, data_format):
......@@ -28,8 +48,13 @@ def _reference_grad(x, grad_y, scale, mean, var, epsilon, data_format):
# grad_x =
# 1/N * scale * rsqrt(var + epsilon) * (N * grad_y - sum(grad_y) -
# (x - mean) * sum(grad_y * (x - mean)) / (var + epsilon))
if data_format != "NHWC":
raise ValueError("data_format must be NHWC, got %s." % data_format)
# transfer from (N, C, H, W) to (N, H, W, C) to simplify computation
if data_format == "NCHW":
x = np.transpose(x, (0, 2, 3, 1))
grad_y = np.transpose(grad_y, (0, 2, 3, 1))
# raise ValueError("data_format must be NHWC, got %s." % data_format)
grad_x = scale * (grad_y - np.mean(
grad_y, axis=(0, 1, 2)) - (x - mean) * np.mean(
grad_y * (x - mean), axis=(0, 1, 2)) /
......@@ -37,6 +62,12 @@ def _reference_grad(x, grad_y, scale, mean, var, epsilon, data_format):
grad_scale = np.sum(grad_y * (x - mean) / np.sqrt(var + epsilon),
axis=(0, 1, 2))
grad_offset = np.sum(grad_y, axis=(0, 1, 2))
# transfer back to N, C, H, W
if data_format == "NCHW":
grad_x = np.transpose(grad_x, (0, 3, 1, 2))
x = np.transpose(x, (0, 3, 1, 2))
grad_y = np.transpose(grad_y, (0, 3, 1, 2))
return grad_x, grad_scale, grad_offset
......@@ -72,39 +103,104 @@ class TestBatchNormOp(OpTest):
def __assert_close(self, tensor, np_array, msg, atol=1e-4):
self.assertTrue(np.allclose(np.array(tensor), np_array, atol=atol), msg)
def test_forward_backward(self):
# attr
def test_python(self):
data_format = "NHWC"
epsilon = 0.00001
momentum = 0.9
# N, H, W, C: 2, 3, 4, 2
channel_num = 2
x_shape = [2, 3, 4, channel_num]
scale_shape = [channel_num]
# input
x_val = np.random.random_sample(x_shape).astype(np.float32)
scale_val = np.random.random_sample(scale_shape).astype(np.float32)
bias_val = np.random.random_sample(scale_shape).astype(np.float32)
mean = np.zeros(scale_shape).astype(np.float32)
variance = np.zeros(scale_shape).astype(np.float32)
variance = np.ones(scale_shape).astype(np.float32)
# run forward
y_out, saved_mean, var_ref = _reference_training(
x_val, scale_val, bias_val, epsilon, "NHWC")
#
mean_out = saved_mean * (1. - momentum) + momentum * mean
variance_out = var_ref * (1. - momentum) + momentum * variance
saved_variance = 1. / np.sqrt(var_ref + epsilon)
# running N, C, H, W case
# should produce the same results
x_shape2 = [2, channel_num, 3, 4]
x_val2 = np.transpose(x_val, (0, 3, 1, 2))
y_out2, saved_mean2, var_ref2 = _reference_training(
x_val2, scale_val, bias_val, epsilon, "NCHW")
self.__assert_close(saved_mean, saved_mean2, "batch mean")
self.__assert_close(var_ref, var_ref2, "batch variance")
# transfer (N, C, H, W) back to (N, H, W, C)
y_out2_trans = np.transpose(y_out2, (0, 2, 3, 1))
self.__assert_close(y_out, y_out2_trans, "batch variance")
print 'python: NHWC, NCHW, forward checking passed'
# test backward now
# NHWC
y_grad = np.ones(x_shape).astype(np.float32)
x_grad_ref, scale_grad_ref, bias_grad_ref = _reference_grad(
x_val, y_grad, scale_val, saved_mean, var_ref, epsilon, "NHWC")
# NCHW
y_grad2 = np.ones(x_shape2).astype(np.float32)
x_grad_ref2, scale_grad_ref2, bias_grad_ref2 = _reference_grad(
x_val2, y_grad2, scale_val, saved_mean2, var_ref2, epsilon, "NCHW")
self.__assert_close(scale_grad_ref, scale_grad_ref2, "scale gradient")
self.__assert_close(bias_grad_ref, bias_grad_ref2, "bias gradient")
x_grad_transpose = np.transpose(x_grad_ref2, (0, 2, 3, 1))
self.__assert_close(x_grad_ref, x_grad_transpose, "x gradient")
print 'python: NHWC, NCHW, backward checking passed'
def test_forward_backward(self):
# attr
data_format = "NCHW"
epsilon = 0.00001
momentum = 0.9
# N, H, W, C: 2, 3, 4, 2
n, h, w, c = 2, 3, 4, 2
if data_format == "NHWC":
x_shape = [n, h, w, c]
elif data_format == "NCHW":
x_shape = [n, c, h, w]
else:
raise ValueError("Unknown data type.")
scale_shape = [c]
x_val = np.random.random_sample(x_shape).astype(np.float32)
scale_val = np.random.random_sample(scale_shape).astype(np.float32)
bias_val = np.random.random_sample(scale_shape).astype(np.float32)
mean = np.zeros(scale_shape).astype(np.float32)
variance = np.ones(scale_shape).astype(np.float32)
# run forward
y_out, saved_mean, var_ref = _reference_training(
x_val, scale_val, bias_val, epsilon, data_format)
# run backward
mean_out = saved_mean * (1 - momentum)
variance_out = var_ref * (1 - momentum)
saved_variance = 1 / np.sqrt(var_ref + epsilon)
# update moving mean and variance
mean_out = saved_mean * (1. - momentum) + momentum * mean
variance_out = var_ref * (1. - momentum) + momentum * variance
saved_variance = 1. / np.sqrt(var_ref + epsilon)
# for gradient test
y_grad = np.ones(x_shape).astype(np.float32)
x_grad_ref, scale_grad_ref, bias_grad_ref = _reference_grad(
x_val, y_grad, scale_val, saved_mean, var_ref, epsilon, data_format)
def test_with_place(place):
def test_with_place(place, tensor_format=data_format):
scope = core.Scope()
# create input
......@@ -142,7 +238,7 @@ class TestBatchNormOp(OpTest):
SavedVariance="saved_variance",
# attrs
is_test=False,
tensor_format=data_format,
tensor_format=tensor_format,
momentum=momentum,
epsilon=epsilon)
......@@ -162,6 +258,7 @@ class TestBatchNormOp(OpTest):
atol = 1e-4
self.__assert_close(variance_out_tensor, variance_out,
"variance_out", atol)
print "op test forward passed: ", tensor_format
# run backward
batch_norm_op_grad = get_backward_op(scope, batch_norm_op, set())
......@@ -185,12 +282,14 @@ class TestBatchNormOp(OpTest):
self.__assert_close(x_grad_tensor, x_grad_ref, "x_grad")
self.__assert_close(scale_grad_tensor, scale_grad_ref, "scale_grad")
self.__assert_close(bias_grad_tensor, bias_grad_ref, "bias_grad")
print "op test backward passed: ", tensor_format
places = [core.CPUPlace()]
if core.is_compile_gpu() and core.op_support_gpu("batch_norm"):
places.append(core.GPUPlace(0))
for place in places:
test_with_place(place)
print "test forward passed"
if __name__ == '__main__':
......
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