I am totally new in both python & tensorflow (<1 week).
Now i want to build a linear regression by using tensorflow, however i am facing an error of placeholder.
I have set the cost by using placeholder, and i have checked the shape of the input variables, it looks no any problem about the shape. I have also use print(type()) to get the type, it shows both newX and Y are class 'numpy.ndarray' .
here is my code: UPDATE:(paste the full code of the class)
class RegByNN(object):
def __init__(self, learning_rate=0.001):
self.learning_rate= learning_rate
def fit(self, X, Y, Xtest, Ytest, TrainLoop=30):
# function try to fit the target to Y
# call forward and loop here
plt.plot(X,Y)
plt.show()
costs = []
# make shape of Y to [?, 1]
shapeOfY = Y.shape
shapeOfY = shapeOfY[0]
Y = Y.reshape(shapeOfY,1)
shapeOfX = X.shape
shapeOfX= int(shapeOfX[0])
# add bise term
B= np.ones(shapeOfX)
newX= np.stack([X, B])
newX = newX.T
m, shapeOfNewX = newX.shape
Xp = tf.placeholder(tf.float32, shape=(m, shapeOfNewX), name='Xp')
y = tf.placeholder(tf.float32, shape=(None,1), name='y')
W1 = tf.Variable(tf.random_normal([shapeOfNewX, m]))
cost = tf.reduce_mean(tf.square(tf.matmul(Xp, W1) - y))
train_op = tf.train.GradientDescentOptimizer(self.learning_rate).minimize(cost)
with tf.Session() as sess:
init = tf.global_variables_initializer()
sess.run(init)
print(type(newX))
print(type(Y))
for step in range(TrainLoop):
sess.run(train_op, feed_dict={Xp: newX, y: Y} )
tempCost= cost.eval()
costs.append(tempCost)
if int(step % (TrainLoop/2)) == 0 :
tempW1= W1.eval()
#tempW2= W2.eval()
print("i = ",step ,"new W1 is: ", tempW1,"new W2 is: ", tempW2.T , "cost: ", tempCost)
tempW1= W1.eval()
tempW2= W2.eval()
print("final W1 is: ", tempW1)
print("new W2 is: ", tempW2.T )
print("cost: ", tempCost)
The following is the error code:
Traceback (most recent call last):
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\client\session.py", line 1350, in _do_call
return fn(*args)
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\client\session.py", line 1329, in _run_fn
status, run_metadata)
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\framework\errors_impl.py", line 473, in __exit__
c_api.TF_GetCode(self.status.status))
tensorflow.python.framework.errors_impl.InvalidArgumentError: You must feed a value for placeholder tensor 'Placeholder_1' with dtype float and shape [?,1]
[[Node: Placeholder_1 = Placeholder[dtype=DT_FLOAT, shape=[?,1], _device="/job:localhost/replica:0/task:0/device:CPU:0"]()]]
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "~~.py", line 87, in <module>
main()
File "~~.py", line 84, in main
model.fit(X, Y, Xtest, Ytest, learning_rate, 40000,20)
File "~~.py", line 47, in fit
tempCost= cost.eval()
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\framework\ops.py", line 648, in eval
return _eval_using_default_session(self, feed_dict, self.graph, session)
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\framework\ops.py", line 4758, in _eval_using_default_session
return session.run(tensors, feed_dict)
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\client\session.py", line 895, in run
run_metadata_ptr)
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\client\session.py", line 1128, in _run
feed_dict_tensor, options, run_metadata)
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\client\session.py", line 1344, in _do_run
options, run_metadata)
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\client\session.py", line 1363, in _do_call
raise type(e)(node_def, op, message)
tensorflow.python.framework.errors_impl.InvalidArgumentError: You must feed a value for placeholder tensor 'Placeholder_1' with dtype float and shape [?,1]
[[Node: Placeholder_1 = Placeholder[dtype=DT_FLOAT, shape=[?,1], _device="/job:localhost/replica:0/task:0/device:CPU:0"]()]]
Caused by op 'Placeholder_1', defined at:
File "~~.py", line 87, in <module>
main()
File "~~.py", line 84, in main
model.fit(X, Y, Xtest, Ytest, learning_rate, 40000,20)
File "~~.py", line 33, in fit
y = tf.placeholder(tf.float32, shape=(None,1))
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\ops\array_ops.py", line 1680, in placeholder
return gen_array_ops._placeholder(dtype=dtype, shape=shape, name=name)
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\ops\gen_array_ops.py", line 4105, in _placeholder
"Placeholder", dtype=dtype, shape=shape, name=name)
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\framework\op_def_library.py", line 787, in _apply_op_helper
op_def=op_def)
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\framework\ops.py", line 3160, in create_op
op_def=op_def)
File "C:\Users\admin\AppData\Local\conda\conda\envs\tensorflow\lib\site-packages\tensorflow\python\framework\ops.py", line 1625, in __init__
self._traceback = self._graph._extract_stack() # pylint: disable=protected-access
InvalidArgumentError (see above for traceback): You must feed a value for placeholder tensor 'Placeholder_1' with dtype float and shape [?,1]
[[Node: Placeholder_1 = Placeholder[dtype=DT_FLOAT, shape=[?,1], _device="/job:localhost/replica:0/task:0/device:CPU:0"]()]]
