我已经实现了下面这个自定义
这个错误似乎与输出的缺失有关(或者输出为None)[但我知道这不是问题所在,因为我已经在急切模式下测试了该函数并且它可行] 或者由于某些原因backprop与此操作(
Layer
,它可以根据输入x
的大小使用函数repeat
来调整学习参数seed_vectors
的大小。import tensorflow as tf
from tensorflow.keras.layers import Dense
from tensorflow import repeat
from tensorflow.keras.layers import LayerNormalization
class PoolingMultiHeadAttention(tf.keras.layers.Layer):
def __init__(self, d, k, h):
"""
Arguments:
d: an integer, input dimension.
k: an integer, number of seed vectors.
h: an integer, number of heads.
"""
super(PoolingMultiHeadAttention, self).__init__()
self.seed_vectors = self.add_weight(initializer='uniform',
shape=(1, k, d),
trainable=True)
def call(self, z):
"""
Arguments:
z: a float tensor with shape [b, n, d].
Returns:
a float tensor with shape [b, k, d]
"""
b = z.shape[0]
s = self.seed_vectors
s = repeat(s, (b), axis=0, name='rep') # shape [b, k, d]
return s*z
# Dimensionality test
z = tf.random.normal(shape=(10, 2, 9))
pma = PoolingMultiHeadAttention(d=9, k=2, h=3)
pma(z)
我在单元测试中测试过输入/输出的维度,效果很好,但是不幸的是,如果我在模型中使用这个层,它会失败并显示以下错误:
<ipython-input-4-89023d123369>:110 call *
s = repeat(s, (b), axis=0, name='rep') # shape [b, k, d]
/usr/local/lib/python3.6/dist-packages/tensorflow/python/ops/array_ops.py:5616 repeat **
return repeat_with_axis(input, repeats, axis, name)
/usr/local/lib/python3.6/dist-packages/tensorflow/python/ops/array_ops.py:5478 repeat_with_axis
repeats = convert_to_int_tensor(repeats, name="repeats")
/usr/local/lib/python3.6/dist-packages/tensorflow/python/ops/array_ops.py:5388 convert_to_int_tensor
tensor = ops.convert_to_tensor(tensor, name=name, preferred_dtype=dtype)
/usr/local/lib/python3.6/dist-packages/tensorflow/python/framework/ops.py:1341 convert_to_tensor
ret = conversion_func(value, dtype=dtype, name=name, as_ref=as_ref)
/usr/local/lib/python3.6/dist-packages/tensorflow/python/framework/constant_op.py:317 _constant_tensor_conversion_function
return constant(v, dtype=dtype, name=name)
/usr/local/lib/python3.6/dist-packages/tensorflow/python/framework/constant_op.py:258 constant
allow_broadcast=True)
/usr/local/lib/python3.6/dist-packages/tensorflow/python/framework/constant_op.py:296 _constant_impl
allow_broadcast=allow_broadcast))
/usr/local/lib/python3.6/dist-packages/tensorflow/python/framework/tensor_util.py:439 make_tensor_proto
raise ValueError("None values not supported.")
ValueError: None values not supported.
这个错误似乎与输出的缺失有关(或者输出为None)[但我知道这不是问题所在,因为我已经在急切模式下测试了该函数并且它可行] 或者由于某些原因backprop与此操作(
repeat
)不兼容。我不知道在运行时修改该参数大小的任何替代方法,并且几乎相同的代码使用Pytorch可以正常工作(https://github.com/TropComplique/set-transformer/blob/master/blocks.py)。谢谢