Instantiates a placeholder tensor and returns it.
tf.keras.backend.placeholder(
shape=None, ndim=None, dtype=None, sparse=False, name=None, ragged=False
)
Arguments |
shape
|
Shape of the placeholder
(integer tuple, may include None entries).
|
ndim
|
Number of axes of the tensor.
At least one of {shape , ndim } must be specified.
If both are specified, shape is used.
|
dtype
|
Placeholder type.
|
sparse
|
Boolean, whether the placeholder should have a sparse type.
|
name
|
Optional name string for the placeholder.
|
ragged
|
Boolean, whether the placeholder should have a ragged type.
In this case, values of 'None' in the 'shape' argument represent
ragged dimensions. For more information about RaggedTensors, see this
guide.
|
Raises |
ValueError
|
If called with eager execution
|
ValueError
|
If called with sparse = True and ragged = True.
|
Returns |
Tensor instance (with Keras metadata included).
|
Examples:
from keras import backend as K
input_ph = K.placeholder(shape=(2, 4, 5))
input_ph
<tf.Tensor 'Placeholder_4:0' shape=(2, 4, 5) dtype=float32>