Extend `qml.cond` #2275

antalszava · 2022-03-03T16:32:14Z

Context:
The addition of qml.cond in #2211 can be extended.

Description of the Change:

Implement MeasurementValue.__invert__ to allow the ~mv syntax
Allow passing an else case to qml.cond
Allow quantum functions to work with qml.cond

Note: further changes to the documentation would follow separately.

Benefits:
More powerful conditional operation structures.

Possible Drawbacks:
N/A

Related GitHub Issues:
N/A

Note: ~ was chosen to "flip" the measurement value instead of not because not involves defining __bool__ that requires a boolean return.

github-actions · 2022-03-03T16:32:34Z

Hello. You may have forgotten to update the changelog!
Please edit doc/releases/changelog-dev.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.

codecov · 2022-03-03T16:49:11Z

Codecov Report

Merging #2275 (c27f50d) into conditional-ops-alpha-sanitized (53ff922) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@                       Coverage Diff                        @@
##           conditional-ops-alpha-sanitized    #2275   +/-   ##
================================================================
  Coverage                            99.31%   99.31%           
================================================================
  Files                                  239      241    +2     
  Lines                                19023    19097   +74     
================================================================
+ Hits                                 18893    18967   +74     
  Misses                                 130      130

Impacted Files	Coverage Δ
pennylane/measurements.py	`99.33% <100.00%> (+0.02%)`	⬆️
pennylane/transforms/condition.py	`100.00% <100.00%> (ø)`
pennylane/qnode.py	`100.00% <0.00%> (ø)`
pennylane/ops/cv.py	`100.00% <0.00%> (ø)`
pennylane/__init__.py	`100.00% <0.00%> (ø)`
pennylane/drawer/tape_text.py	`100.00% <0.00%> (ø)`
pennylane/ops/qubit/__init__.py	`100.00% <0.00%> (ø)`
pennylane/ops/qubit/qchem_ops.py	`100.00% <0.00%> (ø)`
pennylane/tape/cv_param_shift.py	`100.00% <0.00%> (ø)`
pennylane/devices/default_mixed.py	`100.00% <0.00%> (ø)`
... and 10 more

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
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josh146 · 2022-03-04T07:50:18Z

pennylane/measurements.py

+    def __invert__(self):
+        """Inverts the value of the measurement value."""
+        zero = self._zero_case
+        one = self._one_case
+
+        self._control_value = one if self._control_value == zero else zero
+
+        return self


very clean! Minor comment: would the docstring be more accurate to say

"""Inverts the control value of the measurement."""
?

Yep, added.

josh146

Nice work @antalszava! Amazing that you have added important extensions so quickly

pennylane/transforms/condition.py

tests/test_measurements.py

josh146 · 2022-03-04T08:35:13Z

tests/transforms/test_condition.py

+class TestCond:
+    """Tests that verify that the cond transform works as expect."""


Minor: the name of this test class, the docstring, and the fact that it is the only test class, imply that it is not needed. You could remove it and just have test functions in this file.

There is now a class TestOtherTransforms in the file too 😄 What would be the benefit of not having a class btw?

What would be the benefit of not having a class btw?

Oh it's just that test classes don't really do anything, their main use is simply categorization of multiple tests within a module.

I find that if there isn't any categorization needed, it's cleaner to just have test functions.

pennylane/transforms/condition.py

tests/transforms/test_defer_measurements.py

antalszava · 2022-03-04T14:25:39Z

[sc-15616]

Co-authored-by: Josh Izaac <josh146@gmail.com>

…to extend_qml_cond

josh146

@antalszava this is great! Super nice, very excited about this PR.

I'm happy to approve, but only have one major comment regarding the docstring example section.

Ideally, documentation should be contained within the same PR as the feature (as we do with tests), but due to the tight deadline, I understand if this PR is blocking others - as long as finishing the docstring isn't forgotten!

pennylane/transforms/condition.py

josh146 · 2022-03-04T16:17:32Z

tests/transforms/test_condition.py

+        assert ops[2].then_op.wires == target_wire
+        assert ops[2].then_op.data == [r]
+
+        assert isinstance(ops[3], qml.transforms.condition.Conditional)


josh146 · 2022-03-04T16:18:40Z

tests/transforms/test_condition.py

+        assert isinstance(op2.then_op, qml.RY)
+        assert op1.then_op.data == [r]
+
+        assert ops[2].return_type == qml.operation.Probability


Really awesome testing!

tests/transforms/test_defer_measurements.py

josh146 · 2022-03-04T16:21:12Z

pennylane/transforms/condition.py

-        function: A new function that applies the conditional equivalent of ``then_op``. The returned
-        function takes the same input arguments as ``then_op``.
+        function: A new function that applies the conditional equivalent of ``true_fn``. The returned
+        function takes the same input arguments as ``true_fn``.

    **Example**


@antalszava the example here is not up to our usual standards for docstring examples (e.g., it doesn't contain any text explaining the context/code, and showing outputs).

It also seems to be missing:

examples with qfuncs,

examples with then/else, and

examples showing how to deal with conditional functions with different signatures

Co-authored-by: Josh Izaac <josh146@gmail.com>

* better * fixed * fxied * fixed * fixed * fixed * fxied * revert * fixed * cleaner syntax * cleaner syntax * better naming * better naming * fixed code factor * fixed black * fixed docs * fixed types * fixed * progress * fixed docs * better * simplify * simpler now * better design * revert * fixed * better design * optimized * progress * now this is working * progress * progress * simplify * better naming * progress * added for docs * progress * fixed lint * fixing docs * fixed black * fixed linting * consistancy * simplify * progress * simplify * defer_measurement transform & add a measured_qubit attribute * adjust tests * tests * extend reset * refactor * better * progress * dont need * dont need * progress * seems to be working * fixed * progress * progress * progress * progress * progress * progress * might be a good check * simplify * Update pennylane/ops/mid_circuit_measure.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * fixed * progress * fixed * progress * progress * progress * almost there * ok this works * fixed * broken for some reason * progress * simple * I think simpler * simpler * ok * better design * fixed * progress * progress * progress * broken for now * we need to go back to multiple measurements per circuit * progress * now we have a working op * license * imports * no condition or apply mdv * no extras nor tests * merge function into the main func * more tests and boilerplate * less * format * format * more tests * license * drawing test * tests * docstring * docstring * format * template test * format * kwarg test * basis state prep test * CV test, format * docstring * angle embedding * format * section on measurements page * lint format * lint format * lint format * lint format * remove str for now (unused) * changing to qml.If and making some changes to qml.measure * qml.measure module ref -> qml.measurements * measure module ref -> measurements in tests * format * qml.cond; qml.Conditional under the hood * lint; format * include the wires that have already been measured in the error message * correct example * reorganize defs * reorganize defs * Added condition.py * formatting * Apply the defer measurements transform by default in the QNode * add test already measured qubit error * format * qml.state and the defer_measurements transform * use a MeasurementProcess class * format * put mid-circuit measurement processes into tape._ops for now * format * pennylane/measure.py -> pennylane/measurements.py * changelog * no need for pennylane/ops/mid_circuit_measure.py anymore * format * interface tests * draft else op, __eq__ and the likes * docstring * renamed: tests/test_measure.py -> tests/test_measurements.py * MeasurementDependantValue -> MeasurementValue * assertion tests * then_op * condition using measurement outcome * format * no else_op for now * formatting * update the docs part * xfail for now * rephrase * test mcm and conditional via the device base class * too many wires passed to qml.measure * format * linting * lint * lint * format * measure docstring * Conditional docstring * JAX grad test * control on one case * newline * Update pennylane/measurements.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update pennylane/_device.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * RY on 0 * link to def meas princ * RY ref * otherwise * Update doc/introduction/measurements.rst Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update doc/introduction/measurements.rst Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * amend desc * Update pennylane/measurements.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update pennylane/measurements.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update pennylane/measurements.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * revert meas check condition * add cond to operator fun * Update tests/test_measurements.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update pennylane/transforms/condition.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * measurement value * Update pennylane/transforms/condition.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update pennylane/transforms/condition.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * amend qml.cond docstring * no need to apply transform * Update pennylane/transforms/defer_measurements.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * add note to def meas transform * use qml.cond and qml.measure in the example * Update pennylane/transforms/defer_measurements.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update pennylane/transforms/defer_measurements.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update pennylane/transforms/defer_measurements.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * var, probs, sample tests * Add ref to mcm doc section * Test on lightning.qubit too * format * changelog * changelog * adjust the logic in defer_measurements to allow m == 0 case; add integration tests; add lightning to the list of tested devices * format * Update doc/introduction/measurements.rst Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update doc/introduction/measurements.rst Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update doc/introduction/measurements.rst Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update doc/introduction/measurements.rst Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update doc/introduction/measurements.rst Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update doc/releases/changelog-dev.md Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update pennylane/measurements.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update pennylane/measurements.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update pennylane/transforms/condition.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update pennylane/transforms/defer_measurements.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * Update pennylane/transforms/defer_measurements.py Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> * def meas link * TODO: move expansion onto the device * Extend `qml.cond` (#2275) * implement and test __invert__ * add else_op to qml.cond * using inversion in an integration * format * copy measurement under the hood when else; else test * format * err tests * format * docstrings * isort * test_condition * docstrings * format * no need for separate logic for ops * refactor wrapper as per Josh's suggestion from code review * Update tests/transforms/test_defer_measurements.py Co-authored-by: Josh Izaac <josh146@gmail.com> * two unit tests for checking qml.cond queuing * add queue unit tests * format * invert docstring * rename arguments * module docstring * module docstring: note where integration tests are * changelog * Update pennylane/transforms/condition.py Co-authored-by: Josh Izaac <josh146@gmail.com> Co-authored-by: Josh Izaac <josh146@gmail.com> Co-authored-by: Samuel Banning <samcbanning@gmail.com> Co-authored-by: Tom Bromley <49409390+trbromley@users.noreply.github.com> Co-authored-by: Josh Izaac <josh146@gmail.com>

implement and test __invert__

6ba0bac

add else_op to qml.cond

506ad31

antalszava added 12 commits March 3, 2022 11:58

using inversion in an integration

6325507

test inversion

55f665a

format

624362a

copy measurement under the hood when else; else test

96bd3fc

format

2e7b969

err tests

590eb89

format

e5bfd12

docstrings

611389b

isort

aa0372c

test_condition

abafb9c

docstrings

90b0ee5

format

233764d

antalszava marked this pull request as ready for review March 4, 2022 02:43

antalszava requested a review from josh146 March 4, 2022 02:43

josh146 reviewed Mar 4, 2022

View reviewed changes

josh146 requested changes Mar 4, 2022

View reviewed changes

antalszava and others added 9 commits March 4, 2022 09:26

resolve conflict docstring

9ae53c8

no need for separate logic for ops

9eec1c2

refactor wrapper as per Josh's suggestion from code review

58f531a

Update tests/transforms/test_defer_measurements.py

9067e9f

Co-authored-by: Josh Izaac <josh146@gmail.com>

two unit tests for checking qml.cond queuing

3614892

Merge branch 'extend_qml_cond' of github.com:PennyLaneAI/pennylane in…

d55fb16

…to extend_qml_cond

add queue unit tests

e34de5c

format

61a7407

invert docstring

969e1eb

antalszava added 4 commits March 4, 2022 10:46

rename arguments

9a841a7

module docstring

7b968fe

module docstring: note where integration tests are

6109a35

changelog

b03f177

antalszava requested a review from josh146 March 4, 2022 15:55

josh146 approved these changes Mar 4, 2022

View reviewed changes

Update pennylane/transforms/condition.py

c27f50d

Co-authored-by: Josh Izaac <josh146@gmail.com>

antalszava merged commit 0308d78 into conditional-ops-alpha-sanitized Mar 4, 2022

antalszava deleted the extend_qml_cond branch March 4, 2022 19:32

antalszava mentioned this pull request Mar 9, 2022

Extend the conditional operations documentation #2294

Merged

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josh146 mentioned this pull request Mar 14, 2022

Adds Measurement Capabilities to default.qubit #1093

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Extend `qml.cond` #2275

Extend `qml.cond` #2275

antalszava commented Mar 3, 2022 •

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josh146 Mar 4, 2022

		class TestCond:
		"""Tests that verify that the cond transform works as expect."""

Extend qml.cond #2275

Extend qml.cond #2275

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Extend `qml.cond` #2275

Extend `qml.cond` #2275

antalszava commented Mar 3, 2022 •

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codecov bot commented Mar 3, 2022 •

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