我是Tensorflow的新手，正在尝试“波士顿住房价格”的线性回归。 我只是为了练习而使用整个数据集作为训练集。
dataset_input是输入的训练示例。
dataset_output是输出培训示例。
X，Y已用作占位符，它将从我刚刚描述的上述2个变量中获取输入，然后将其输入sess.run(train,feed_dict={X:dataset_input,Y:dataset_output})下的feed_dict中。
但是在代码中的某个地方，我得到了这个错误：
InvalidArgumentError: You must feed a value for placeholder tensor 'Placeholder_2' with dtype float
[[Node: Placeholder_2 = Placeholder[dtype=DT_FLOAT, shape=[], _device="/job:localhost/replica:0/task:0/cpu:0
这里是代码：
import tensorflow as tf
import numpy as np
import pandas as pd
from sklearn.datasets import load_boston
import matplotlib.pyplot as plt
boston=load_boston()
type(boston)
boston.feature_names
bd=pd.DataFrame(data=boston.data,columns=boston.feature_names)
bd['Price']=pd.DataFrame(data=boston.target)
np.random.shuffle(bd.values)
#bd.describe()
#bd.dtypes.index
W=tf.Variable(0.0)
b=tf.Variable(0.0)
print(bd.shape[1])
dataset_input=bd.iloc[:, 0 : bd.shape[1]-1];
dataset_input.head(2)
dataset_output=bd.iloc[:, bd.shape[1]-1]
dataset_output=dataset_output.values
dataset_output=dataset_output.reshape((bd.shape[0],1))#converted (506,) to (506,1) because in pandas
#the shape was not changing and it was needed later in feed_dict
#dataset_output.head(2)
print("Output.shape=",dataset_output.shape)
print("Input.shape=",dataset_input.shape)
X=tf.placeholder(tf.float32, shape=(None,bd.shape[1]-1))
Y=tf.placeholder(tf.float32, shape=(None,1))
Y_=W*X+b
print(X.shape)
print(Y.shape)
#Y_=tf.convert_to_tensor(dataset_output)
loss=tf.reduce_mean(tf.square(Y_-Y))
optimizer=tf.train.GradientDescentOptimizer(0.5)
train=optimizer.minimize(loss)
init=tf.global_variables_initializer()#tf.global_variables_initializer()#tf.initialize_all_variables()
sess=tf.Session()
sess.run(init)
with tf.Session() as sess:
epochs=1000
sess.run(init)
points=[ [],[] ]
for i in range(epochs):
sess.run(train,feed_dict={X:dataset_input,Y:dataset_output})# cannot understand whether the error is here ?
if(i%10==0):
points[0].append(1+i)
points[1].append(sess.run(loss))
if(i%100==0):
print(i+1,sess.run(cost))
plt.plot(points[0],points[1],'r--')
plt.axis([0,epochs,50,600])#
plt.show()
回溯为：
14
Output.shape= (506, 1)
Input.shape= (506, 13)
(?, 13)
(?, 1)
---------------------------------------------------------------------------
InvalidArgumentError Traceback (most recent call last)
~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/client/session.py in _do_call(self, fn, *args)
1038 try:
-> 1039 return fn(*args)
1040 except errors.OpError as e:
~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/client/session.py in _run_fn(session, feed_dict, fetch_list, target_list, options, run_metadata)
1020 feed_dict, fetch_list, target_list,
-> 1021 status, run_metadata)
1022
~/anaconda3/envs/Tensorflow/lib/python3.6/contextlib.py in __exit__(self, type, value, traceback)
87 try:
---> 88 next(self.gen)
89 except StopIteration:
~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/framework/errors_impl.py in raise_exception_on_not_ok_status()
465 compat.as_text(pywrap_tensorflow.TF_Message(status)),
--> 466 pywrap_tensorflow.TF_GetCode(status))
467 finally:
InvalidArgumentError: You must feed a value for placeholder tensor 'Placeholder_2' with dtype float
[[Node: Placeholder_2 = Placeholder[dtype=DT_FLOAT, shape=[], _device="/job:localhost/replica:0/task:0/cpu:0"]()]]
During handling of the above exception, another exception occurred:
InvalidArgumentError Traceback (most recent call last)
<ipython-input-35-520f8b9256aa> in <module>()
60 if(i%10==0):
61 points[0].append(1+i)
---> 62 points[1].append(sess.run(loss))
63 if(i%100==0):
64 print(i+1,sess.run(cost))
~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/client/session.py in run(self, fetches, feed_dict, options, run_metadata)
776 try:
777 result = self._run(None, fetches, feed_dict, options_ptr,
--> 778 run_metadata_ptr)
779 if run_metadata:
780 proto_data = tf_session.TF_GetBuffer(run_metadata_ptr)
~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/client/session.py in _run(self, handle, fetches, feed_dict, options, run_metadata)
980 if final_fetches or final_targets:
981 results = self._do_run(handle, final_targets, final_fetches,
--> 982 feed_dict_string, options, run_metadata)
983 else:
984 results = []
~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/client/session.py in _do_run(self, handle, target_list, fetch_list, feed_dict, options, run_metadata)
1030 if handle is None:
1031 return self._do_call(_run_fn, self._session, feed_dict, fetch_list,
-> 1032 target_list, options, run_metadata)
1033 else:
1034 return self._do_call(_prun_fn, self._session, handle, feed_dict,
~/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/client/session.py in _do_call(self, fn, *args)
1050 except KeyError:
1051 pass
-> 1052 raise type(e)(node_def, op, message)
1053
1054 def _extend_graph(self):
InvalidArgumentError: You must feed a value for placeholder tensor 'Placeholder_2' with dtype float
[[Node: Placeholder_2 = Placeholder[dtype=DT_FLOAT, shape=[], _device="/job:localhost/replica:0/task:0/cpu:0"]()]]
Caused by op 'Placeholder_2', defined at:
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/runpy.py", line 193, in _run_module_as_main
"__main__", mod_spec)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/runpy.py", line 85, in _run_code
exec(code, run_globals)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel_launcher.py", line 16, in <module>
app.launch_new_instance()
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/traitlets/config/application.py", line 658, in launch_instance
app.start()
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel/kernelapp.py", line 486, in start
self.io_loop.start()
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tornado/platform/asyncio.py", line 127, in start
self.asyncio_loop.run_forever()
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/asyncio/base_events.py", line 421, in run_forever
self._run_once()
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/asyncio/base_events.py", line 1431, in _run_once
handle._run()
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/asyncio/events.py", line 145, in _run
self._callback(*self._args)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tornado/platform/asyncio.py", line 117, in _handle_events
handler_func(fileobj, events)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tornado/stack_context.py", line 276, in null_wrapper
return fn(*args, **kwargs)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/zmq/eventloop/zmqstream.py", line 450, in _handle_events
self._handle_recv()
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/zmq/eventloop/zmqstream.py", line 480, in _handle_recv
self._run_callback(callback, msg)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/zmq/eventloop/zmqstream.py", line 432, in _run_callback
callback(*args, **kwargs)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tornado/stack_context.py", line 276, in null_wrapper
return fn(*args, **kwargs)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel/kernelbase.py", line 283, in dispatcher
return self.dispatch_shell(stream, msg)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel/kernelbase.py", line 233, in dispatch_shell
handler(stream, idents, msg)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel/kernelbase.py", line 399, in execute_request
user_expressions, allow_stdin)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel/ipkernel.py", line 208, in do_execute
res = shell.run_cell(code, store_history=store_history, silent=silent)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/ipykernel/zmqshell.py", line 537, in run_cell
return super(ZMQInteractiveShell, self).run_cell(*args, **kwargs)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/IPython/core/interactiveshell.py", line 2662, in run_cell
raw_cell, store_history, silent, shell_futures)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/IPython/core/interactiveshell.py", line 2785, in _run_cell
interactivity=interactivity, compiler=compiler, result=result)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/IPython/core/interactiveshell.py", line 2903, in run_ast_nodes
if self.run_code(code, result):
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/IPython/core/interactiveshell.py", line 2963, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "<ipython-input-35-520f8b9256aa>", line 37, in <module>
X=tf.placeholder(tf.float32, shape=(None,bd.shape[1]-1))
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/ops/array_ops.py", line 1507, in placeholder
name=name)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/ops/gen_array_ops.py", line 1997, in _placeholder
name=name)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/framework/op_def_library.py", line 768, in apply_op
op_def=op_def)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/framework/ops.py", line 2336, in create_op
original_op=self._default_original_op, op_def=op_def)
File "/Users/ajay/anaconda3/envs/Tensorflow/lib/python3.6/site-packages/tensorflow/python/framework/ops.py", line 1228, in __init__
self._traceback = _extract_stack()
InvalidArgumentError (see above for traceback): You must feed a value for placeholder tensor 'Placeholder_2' with dtype float
[[Node: Placeholder_2 = Placeholder[dtype=DT_FLOAT, shape=[], _device="/job:localhost/replica:0/task:0/cpu:0"]()]]
答案 0 :(得分：1)
您要馈入X的值dataset_input是大熊猫DataFrame，而不是Tensorflow期望的适当的numpy ndarray。
简单地定义例如dataset_input = boston.data应该在这里工作。