tf.compat.v1.assign_sub

Update ref by subtracting value from it.

tf.compat.v1.assign_sub(
    ref, value, use_locking=None, name=None
)

Migrate to TF2

tf.compat.v1.assign_sub is mostly compatible with eager execution and tf.function.

To switch to the native TF2 style, one could use method 'assign_sub' of tf.Variable:

How to Map Arguments

TF1 Arg Name	TF2 Arg Name	Note
`ref`	`self`	In `assign_sub()` method
`value`	`value`	In `assign_sub()` method
`use_locking`	`use_locking`	In `assign_sub()` method
`name`	`name`	In `assign_sub()` method
-	`read_value`	Set to True to replicate behavior (True is default)

Before & After Usage Example

Before:

with tf.Graph().as_default():
  with tf.compat.v1.Session() as sess:
    a = tf.compat.v1.Variable(1, dtype=tf.int64)
    sess.run(a.initializer)
    update_op = tf.compat.v1.assign_sub(a, 1)
    res_a = sess.run(update_op)
    res_a
0

After:

b = tf.Variable(1, dtype=tf.int64)
res_b = b.assign_sub(1)
res_b.numpy()
0

Description

This operation outputs ref after the update is done. This makes it easier to chain operations that need to use the reset value. Unlike tf.math.subtract, this op does not broadcast. ref and value must have the same shape.

Args
`ref`	A mutable `Tensor`. Must be one of the following types: `float32`, `float64`, `int64`, `int32`, `uint8`, `uint16`, `int16`, `int8`, `complex64`, `complex128`, `qint8`, `quint8`, `qint32`, `half`. Should be from a `Variable` node.
`value`	A `Tensor`. Must have the same shape and dtype as `ref`. The value to be subtracted to the variable.
`use_locking`	An optional `bool`. Defaults to `False`. If True, the subtraction will be protected by a lock; otherwise the behavior is undefined, but may exhibit less contention.
`name`	A name for the operation (optional).

Returns
Same as `ref`. Returned as a convenience for operations that want to use the new value after the variable has been updated.