Add support for the parameter-shift hessian to the TF interface #1110

albi3ro · 2021-02-24T20:33:31Z

This pull request ties in the parameter shift hessian calculation to the tensorflow interface.

Now you should be able to run:

dev = qml.device('default.qubit', wires=1)
@qml.qnode(dev, interface='tf', diff_method='parameter-shift')
def circuit(x):
    qml.RX(x[0], wires=0)
    qml.RY(x[1], wires=0)
    return qml.expval(qml.PauliZ(0))

x = tf.Variable([0.1, 0.2], dtype=tf.float64)

with tf.GradientTape() as tape1:
    with tf.GradientTape() as tape2:
        y = circuit(x)
    grad = tape2.gradient(res, x)

tape1.jacobian(grad, x)

github-actions · 2021-02-24T20:33:55Z

Hello. You may have forgotten to update the changelog!
Please edit .github/CHANGELOG.md with:

A one-to-two sentence description of the change. You may include a small working example for new features.
A link back to this PR.
Your name (or GitHub username) in the contributors section.

* fix * fix

codecov · 2021-03-22T10:24:25Z

Codecov Report

Merging #1110 (9825917) into master (6e22257) will increase coverage by 0.00%.
The diff coverage is 97.05%.

@@           Coverage Diff           @@
##           master    #1110   +/-   ##
=======================================
  Coverage   98.11%   98.11%           
=======================================
  Files         144      144           
  Lines       10775    10794   +19     
=======================================
+ Hits        10572    10591   +19     
  Misses        203      203

Impacted Files	Coverage Δ
pennylane/tape/jacobian_tape.py	`97.83% <85.71%> (-0.51%)`	⬇️
pennylane/interfaces/tf.py	`97.14% <100.00%> (+0.77%)`	⬆️
pennylane/tape/qubit_param_shift.py	`100.00% <0.00%> (+0.82%)`	⬆️

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 6e22257...9825917. Read the comment docs.

trbromley

Thanks @albi3ro! Really cool to see Hessian support coming in for the various interfaces 💯

.github/CHANGELOG.md

trbromley · 2021-03-22T23:38:31Z

tests/tape/test_jacobian_tape.py

@@ -606,7 +606,7 @@ def test_non_differentiable_error(self):
            qml.RX(0.543, wires=[0])
            qml.RY(-0.654, wires=[1])
            qml.CNOT(wires=[0, 1])
-            qml.probs(wires=[0, 1])
+            qml.expval(qml.PauliZ(0))


What was the reason for this change?

@albi3ro was this change you or me?

I changed it back when we couldn't support calculate the hessian of a vector-valued output. We can now take the hessian of a vector valued function, so I'm changing it back.

@albi3ro in retrospect this was actually a good change, as it increased coverage! I think if you change it back again (sorry 😬 ) codecov will pass and this can be merged in)

pennylane/interfaces/tf.py

trbromley · 2021-03-22T23:48:01Z

pennylane/interfaces/tf.py

+
+            @tf.custom_gradient
+            def jacobian(p):
+                def hessian_product(ddy, **tfkwargs):


Not a problem for this PR, but this nested structure seems a not very maintainable way to provide higher-order gradients. I wonder why this is the standard approach.

Because second derivatives and custom gradients are both not very common in current ML models 😆

trbromley · 2021-03-22T23:57:08Z

tests/interfaces/test_qnode_tf.py

+                [-0.5 * tf.sin(a) * tf.sin(b), 0.5 * tf.cos(a) * tf.cos(b)]
+            ]
+        ]
+        np.testing.assert_allclose(hess, expected_hess, atol=tol, rtol=0, verbose=True)


Nice, I didn't know about np.testing.assert_allclose(). Is there any advantage over assert np.allclose()? 🤔

Also curious! 🤔

np.testing.assert_allclose() provides a better traceback on failure, showing the full arrays it is trying to compare!

.github/CHANGELOG.md

pennylane/interfaces/tf.py

thisac

Looks nice @albi3ro! 👍

pennylane/interfaces/tf.py

thisac · 2021-03-23T20:25:18Z

tests/interfaces/test_qnode_tf.py

+                [-0.5 * tf.sin(a) * tf.sin(b), 0.5 * tf.cos(a) * tf.cos(b)]
+            ]
+        ]
+        np.testing.assert_allclose(hess, expected_hess, atol=tol, rtol=0, verbose=True)


Also curious! 🤔

Co-authored-by: Theodor <theodor@xanadu.ai>

josh146

@albi3ro feel free to merge this one in!

tests/tape/test_jacobian_tape.py

…into hessian_tf

prototyping for hessian computation in tensorflow interface

5cdf911

albi3ro added the WIP 🚧 Work-in-progress label Feb 24, 2021

albi3ro and others added 10 commits February 24, 2021 14:54

add changelog

67b4b7b

more changes

ffb44df

more stuff

118b5a1

qnode test

c82ddb8

Add support for computing the Hessian for vector-valued QNodes (#1122)

7a546ef

* fix * fix

add additional test

24f4258

fix

1be77f0

fix

d812fcb

Fix interface

be3d541

Merge branch 'master' into hessian_tf

27c8dbd

josh146 mentioned this pull request Mar 19, 2021

Add support for the parameter-shift hessian to the Torch interface #1129

Merged

josh146 changed the title ~~[WIP] hessian computation in tensorflow interface~~ Add support for the parameter-shift hessian to the TF interface Mar 22, 2021

josh146 requested review from trbromley, josh146 and thisac March 22, 2021 08:30

josh146 added 2 commits March 22, 2021 16:34

merge master

c03b0ed

fix

32c817e

josh146 removed the WIP 🚧 Work-in-progress label Mar 22, 2021

josh146 added 3 commits March 22, 2021 17:59

fix test

471b8da

fix

9474324

fix

7813490

trbromley approved these changes Mar 22, 2021

View reviewed changes

josh146 reviewed Mar 23, 2021

View reviewed changes

.github/CHANGELOG.md Outdated Show resolved Hide resolved

Update .github/CHANGELOG.md

5da8521

josh146 reviewed Mar 23, 2021

View reviewed changes

pennylane/interfaces/tf.py Show resolved Hide resolved

Update pennylane/interfaces/tf.py

49a2df9

josh146 added 2 commits March 23, 2021 20:36

Merge branch 'master' into hessian_tf

5faeeb1

Merge branch 'master' into hessian_tf

032a5d0

thisac approved these changes Mar 23, 2021

View reviewed changes

josh146 and others added 3 commits March 24, 2021 13:25

Merge branch 'master' into hessian_tf

50702ae

Update pennylane/interfaces/tf.py

6b48840

Co-authored-by: Theodor <theodor@xanadu.ai>

suggested changes

61e1a92

josh146 approved these changes Mar 24, 2021

View reviewed changes

josh146 and others added 7 commits March 24, 2021 23:52

Merge branch 'master' into hessian_tf

cc8f979

Merge branch 'master' into hessian_tf

b4372b7

Merge branch 'master' into hessian_tf

9d65ac1

minor updates

62b77a6

comment updates

c69879d

comment indentation

fb5cad3

minor fix

c6fbcd0

albi3ro commented Mar 26, 2021

View reviewed changes

tests/tape/test_jacobian_tape.py Outdated Show resolved Hide resolved

albi3ro and others added 6 commits March 26, 2021 09:27

Update tests/tape/test_jacobian_tape.py

be02d87

Merge branch 'master' into hessian_tf

e1fdcb3

add test for vector function hessian tape

5fabbda

Merge branch 'hessian_tf' of https://github.com/PennyLaneAI/pennylane …

3ec0ba7

…into hessian_tf

fix test

3ac6b74

Merge branch 'master' into hessian_tf

9825917

albi3ro merged commit 2069021 into master Mar 26, 2021

albi3ro deleted the hessian_tf branch March 26, 2021 16:21

josh146 mentioned this pull request Apr 29, 2021

Gradient computation with backpropagation slower than param-shift with TensorFlow interface #1244

Closed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Add support for the parameter-shift hessian to the TF interface #1110

Add support for the parameter-shift hessian to the TF interface #1110

albi3ro commented Feb 24, 2021

github-actions bot commented Feb 24, 2021

codecov bot commented Mar 22, 2021 •

edited

Loading

trbromley left a comment

trbromley Mar 22, 2021

josh146 Mar 23, 2021

josh146 Mar 24, 2021

albi3ro Mar 25, 2021

josh146 Mar 26, 2021

trbromley Mar 22, 2021

josh146 Mar 23, 2021

trbromley Mar 22, 2021

thisac Mar 23, 2021

josh146 Mar 24, 2021

thisac left a comment

thisac Mar 23, 2021

josh146 left a comment

Add support for the parameter-shift hessian to the TF interface #1110

Add support for the parameter-shift hessian to the TF interface #1110

Conversation

albi3ro commented Feb 24, 2021

github-actions bot commented Feb 24, 2021

codecov bot commented Mar 22, 2021 • edited Loading

Codecov Report

trbromley left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

thisac left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

josh146 left a comment

Choose a reason for hiding this comment

codecov bot commented Mar 22, 2021 •

edited

Loading