我正在尝试为Android构建离线翻译器。我的模型从该指南中得到了极大的启发:https : //www.tensorflow.org/tutorials/text/nmt_with_attention。我只是做了一些修改以确保模型可序列化。(您可以在最后找到该模型的代码)
该模型可以在我的jupyter笔记本上完美运行。我正在使用Tensorflow版本:2.3.0-dev20200617,我也能够使用以下代码段生成tflite文件:
converter = tf.lite.TFLiteConverter.from_keras_model(partial_model)
tflite_model = converter.convert()
with tf.io.gfile.GFile('goog_nmt_v2.tflite', 'wb') as f:
f.write(tflite_model)
但是,当我使用生成的tflite模型在android上进行预测时,会引发错误 java.lang.IllegalArgumentException: Internal error: Failed to run on the given Interpreter: tensorflow/lite/kernels/concatenation.cc:73 t->dims->data[d] != t0->dims->data[d] (8 != 1) Node number 84 (CONCATENATION) failed to prepare.
这很奇怪,因为我提供了与在jupyter笔记本中完全一样的输入尺寸。这是用于测试(虚拟输入)模型是否在android上运行的Java代码:
HashMap<Integer, Object> outputVal = new HashMap<>();
for(int i=0; i<2; i++) outputVal.put(i, new float[1][5]);
float[][] inp_test = new float[1][8];
float[][] enc_hidden = new float[1][1024];
float[][] dec_input = new float[1][1];
float[][] dec_test = new float[1][8];
tfLite.runForMultipleInputsOutputs(new Object[] {inp_test,enc_hidden, dec_input, dec_test},outputVal);
这是我的gradle依赖项:
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'androidx.appcompat:appcompat:1.1.0'
implementation 'org.tensorflow:tensorflow-lite:0.0.0-nightly'
implementation 'org.tensorflow:tensorflow-lite-select-tf-ops:0.0.0-nightly'
// This dependency adds the necessary TF op support.
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test.ext:junit:1.1.1'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}
正如错误所指出的那样,节点84的尺寸存在问题。因此,我继续使用Netron可视化tflite文件。我放大了串联节点,可以在此处找到该节点的图片以及输入和输出尺寸。您可以在此处找到整个生成的图形。
事实证明,位置84的串联节点实际上不是串联的,您可以从输入和输出维度中看到这一点。处理完1X1X1和1X1X256矩阵后,它只会吐出1X1X1矩阵。我知道tflite图与原始模型图并不相同,因为为了优化,很多操作被替换甚至删除,但这似乎有些奇怪。
我不能将此与错误相关联。如果它完美地在jupyter上运行,是框架问题还是我缺少了什么?另外,有人可以向我解释t->dims->data[d] != t0->dims->data[d]
d是什么错误吗?
如果您对任何一个问题都有答案,请写下。如果您需要任何其他详细信息,请告诉我。
这是模型的代码:
Tx = 8
def Partial_model():
outputs = []
X = tf.keras.layers.Input(shape=(Tx,))
partial = tf.keras.layers.Input(shape=(Tx,))
enc_hidden = tf.keras.layers.Input(shape=(units,))
dec_input = tf.keras.layers.Input(shape=(1,))
d_i = dec_input
e_h = enc_hidden
X_i = X
enc_output, e_h = encoder(X, enc_hidden)
dec_hidden = enc_hidden
print(dec_input.shape, 'inp', dec_hidden.shape, 'dec_hidd')
for t in range(1, Tx):
print(t, 'tt')
# passing enc_output to the decoder
predictions, dec_hidden, _ = decoder(d_i, dec_hidden, enc_output)
# outputs.append(predictions)
print(predictions.shape, 'pred')
d_i = tf.reshape(partial[:, t], (-1, 1))
print(dec_input.shape, 'dec_input')
predictions, dec_hidden, _ = decoder(d_i, dec_hidden, enc_output)
d_i = tf.squeeze(d_i)
outputs.append(tf.math.top_k(predictions, 5))
return tf.keras.Model(inputs = [X, enc_hidden, dec_input, partial], outputs = [outputs[0][0], outputs[0][1]])
class Encoder():
def __init__(self, vocab_size, embedding_dim, enc_units, batch_sz):
self.batch_sz = batch_sz
self.enc_units = enc_units
self.embedding = tf.keras.layers.Embedding(vocab_size, embedding_dim)
self.gru = tf.keras.layers.GRU(self.enc_units,
return_sequences=True,
return_state=True,
recurrent_initializer='glorot_uniform')
def __call__(self, x, hidden):
x = self.embedding(x)
output, state = self.gru(x, initial_state = hidden)
print(output.shape, hidden.shape, "out", "hid")
return output, state
def initialize_hidden_state(self):
return tf.zeros((self.batch_sz, self.enc_units))
class BahdanauAttention():
def __init__(self, units):
self.W1 = tf.keras.layers.Dense(units)
self.W2 = tf.keras.layers.Dense(units)
self.V = tf.keras.layers.Dense(1)
def __call__(self, query, values):
# query hidden state shape == (batch_size, hidden size)
# query_with_time_axis shape == (batch_size, 1, hidden size)
# values shape == (batch_size, max_len, hidden size)
# we are doing this to broadcast addition along the time axis to calculate the score
print(query.shape, 'shape')
query_with_time_axis = tf.expand_dims(query, 1)
# score shape == (batch_size, max_length, 1)
# we get 1 at the last axis because we are applying score to self.V
# the shape of the tensor before applying self.V is (batch_size, max_length, units)
print("2")
score = self.V(tf.nn.tanh(
self.W1(query_with_time_axis) + self.W2(values)))
print("3")
# attention_weights shape == (batch_size, max_length, 1)
attention_weights = tf.nn.softmax(score, axis=1)
# context_vector shape after sum == (batch_size, hidden_size)
context_vector = attention_weights * values
context_vector = tf.reduce_sum(context_vector, axis=1)
return context_vector, attention_weights
class Decoder():
def __init__(self, vocab_size, embedding_dim, dec_units, batch_sz):
self.dec_units = dec_units
self.embedding = tf.keras.layers.Embedding(vocab_size, embedding_dim)
self.gru = tf.keras.layers.GRU(self.dec_units,
return_sequences=True,
return_state=True,
recurrent_initializer='glorot_uniform')
self.fc = tf.keras.layers.Dense(vocab_size)
# used for attention
self.attention = BahdanauAttention(self.dec_units)
def __call__(self, x, hidden, enc_output):
# enc_output shape == (batch_size, max_length, hidden_size)
context_vector, attention_weights = self.attention(hidden, enc_output)
print(context_vector.shape, 'c_v', attention_weights.shape, "attention_w")
# x shape after passing through embedding == (batch_size, 1, embedding_dim)
x = self.embedding(x)
# x shape after concatenation == (batch_size, 1, embedding_dim + hidden_size)
print(x.shape, 'xshape', context_vector.shape, 'context')
expanded_dims = tf.expand_dims(context_vector, 1)
x = tf.concat([expanded_dims, x], axis=-1)
# passing the concatenated vector to the GRU
output, state = self.gru(x)
# output shape == (batch_size * 1, hidden_size)
output = tf.reshape(output, (-1, output.shape[2]))
# output shape == (batch_size, vocab)
x = self.fc(output)
return x, state, attention_weights
您可以将生成的.tflite文件加载到python笔记本中,并传递与Keras模型相同的输入。您必须查看准确的输出,因为在模型转换期间不会损失准确性。如果有问题...在Android操作过程中会出现问题。如果没有,那么一切都会正常。使用Tensorflow指南中的以下代码在Python中运行推理:
import numpy as np
import tensorflow as tf
# Load the TFLite model and allocate tensors.
interpreter = tf.lite.Interpreter(model_path="converted_model.tflite")
interpreter.allocate_tensors()
# Get input and output tensors.
input_details = interpreter.get_input_details()
output_details = interpreter.get_output_details()
# Test the model on random input data.
input_shape = input_details[0]['shape']
input_data = np.array(np.random.random_sample(input_shape), dtype=np.float32)
interpreter.set_tensor(input_details[0]['index'], input_data)
interpreter.invoke()
# The function `get_tensor()` returns a copy of the tensor data.
# Use `tensor()` in order to get a pointer to the tensor.
output_data = interpreter.get_tensor(output_details[0]['index'])
print(output_data)
祝您编码愉快!
本文收集自互联网,转载请注明来源。
如有侵权,请联系 [email protected] 删除。
我来说两句