tf.keras.backend.placeholder
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>