Merge pull request #866 from qutech/issues/865_time_reversal_program_builder

Add test and implementation for TimeReversalPulseTemplate ProgramBuilder support

Author: Nomos11

qupulse/expressions/sympy.py

@@ -444,7 +444,7 @@ def _try_to_numeric(self) -> Optional[numbers.Number]:
             return None
         if isinstance(self._original_expression, ALLOWED_NUMERIC_SCALAR_TYPES):
             return self._original_expression
-        expr = self._sympified_expression
+        expr = self._sympified_expression.doit()
         if isinstance(expr, bool):
             # sympify can return bool
             return expr

qupulse/program/linspace.py

@@ -44,6 +44,19 @@ class LinSpaceNode:
     def dependencies(self) -> Mapping[int, set]:
         raise NotImplementedError
 
+    def reversed(self, offset: int, lengths: list):
+        """Get the time reversed version of this linspace node. Since this is a non-local operation the arguments give
+        the context.
+
+        Args:
+            offset:  Active iterations that are not reserved
+            lengths: Lengths of the currently active iterations that have to be reversed
+
+        Returns:
+            Time reversed version.
+        """
+        raise NotImplementedError
+
 
 @dataclass
 class LinSpaceHold(LinSpaceNode):
@@ -60,13 +73,46 @@ def dependencies(self) -> Mapping[int, set]:
                 for idx, factors in enumerate(self.factors)
                 if factors}
 
+    def reversed(self, offset: int, lengths: list):
+        if not lengths:
+            return self
+        # If the iteration length is `n`, the starting point is shifted by `n - 1`
+        steps = [length - 1 for length in lengths]
+        bases = []
+        factors = []
+        for ch_base, ch_factors in zip(self.bases, self.factors):
+            if ch_factors is None or len(ch_factors) <= offset:
+                bases.append(ch_base)
+                factors.append(ch_factors)
+            else:
+                ch_reverse_base = ch_base + sum(step * factor
+                                                for factor, step in zip(ch_factors[offset:], steps))
+                reversed_factors = ch_factors[:offset] + tuple(-f for f in ch_factors[offset:])
+                bases.append(ch_reverse_base)
+                factors.append(reversed_factors)
+
+        if self.duration_factors is None or len(self.duration_factors) <= offset:
+            duration_factors = self.duration_factors
+            duration_base = self.duration_base
+        else:
+            duration_base = self.duration_base + sum((step * factor
+                                                      for factor, step in zip(self.duration_factors[offset:], steps)), TimeType(0))
+            duration_factors = self.duration_factors[:offset] + tuple(-f for f in self.duration_factors[offset:])
+        return LinSpaceHold(tuple(bases), tuple(factors), duration_base=duration_base, duration_factors=duration_factors)
+
 
 @dataclass
 class LinSpaceArbitraryWaveform(LinSpaceNode):
     """This is just a wrapper to pipe arbitrary waveforms through the system."""
     waveform: Waveform
     channels: Tuple[ChannelID, ...]
 
+    def reversed(self, offset: int, lengths: list):
+        return LinSpaceArbitraryWaveform(
+            waveform=self.waveform.reversed(),
+            channels=self.channels,
+        )
+
 
 @dataclass
 class LinSpaceRepeat(LinSpaceNode):
@@ -81,6 +127,9 @@ def dependencies(self):
                 dependencies.setdefault(idx, set()).update(deps)
         return dependencies
 
+    def reversed(self, offset: int, counts: list):
+        return LinSpaceRepeat(tuple(node.reversed(offset, counts) for node in reversed(self.body)), self.count)
+
 
 @dataclass
 class LinSpaceIter(LinSpaceNode):
@@ -100,6 +149,12 @@ def dependencies(self):
                     dependencies.setdefault(idx, set()).update(shortened)
         return dependencies
 
+    def reversed(self, offset: int, lengths: list):
+        lengths.append(self.length)
+        reversed_iter = LinSpaceIter(tuple(node.reversed(offset, lengths) for node in reversed(self.body)), self.length)
+        lengths.pop()
+        return reversed_iter
+
 
 class LinSpaceBuilder(ProgramBuilder):
     """This program builder supports efficient translation of pulse templates that use symbolic linearly
@@ -214,6 +269,14 @@ def with_iteration(self, index_name: str, rng: range,
         if cmds:
             self._stack[-1].append(LinSpaceIter(body=tuple(cmds), length=len(rng)))
 
+    @contextlib.contextmanager
+    def time_reversed(self) -> ContextManager['LinSpaceBuilder']:
+        self._stack.append([])
+        yield self
+        inner = self._stack.pop()
+        offset = len(self._ranges)
+        self._stack[-1].extend(node.reversed(offset, []) for node in reversed(inner))
+
     def to_program(self) -> Optional[Sequence[LinSpaceNode]]:
         if self._root():
             return self._root()
@@ -414,8 +477,10 @@ def to_increment_commands(linspace_nodes: Sequence[LinSpaceNode]) -> List[Comman
 
 
 class LinSpaceVM:
-    def __init__(self, channels: int):
+    def __init__(self, channels: int,
+                 sample_resolution: TimeType = TimeType.from_fraction(1, 2)):
         self.current_values = [np.nan] * channels
+        self.sample_resolution = sample_resolution
         self.time = TimeType(0)
         self.registers = tuple({} for _ in range(channels))
 
@@ -428,7 +493,20 @@ def __init__(self, channels: int):
 
     def change_state(self, cmd: Union[Set, Increment, Wait, Play]):
         if isinstance(cmd, Play):
-            raise NotImplementedError("TODO: Implement arbitrary waveform simulation")
+            dt = self.sample_resolution
+            t = TimeType(0)
+            total_duration = cmd.waveform.duration
+            while t <= total_duration and dt > 0:
+                sample_time = np.array([float(t)])
+                values = []
+                for (idx, ch) in enumerate(cmd.channels):
+                    self.current_values[idx] = values.append(cmd.waveform.get_sampled(channel=ch, sample_times=sample_time)[0])
+                self.history.append(
+                    (self.time, self.current_values.copy())
+                )
+                dt = min(total_duration - t, self.sample_resolution)
+                self.time += dt
+                t += dt
         elif isinstance(cmd, Wait):
             self.history.append(
                 (self.time, self.current_values.copy())

qupulse/program/waveforms.py

@@ -1277,3 +1277,6 @@ def compare_key(self) -> Hashable:
 
     def reversed(self) -> 'Waveform':
         return self._inner
+
+    def __repr__(self):
+        return f"ReversedWaveform(inner={self._inner!r})"

tests/expressions/expression_tests.py

@@ -428,6 +428,10 @@ def test_special_function_numeric_evaluation(self):
 
         np.testing.assert_allclose(expected, result)
 
+    def test_try_to_numeric(self):
+        expr = ExpressionScalar('Sum(9, (x, 0, 5), (y, 0, 7))')
+        self.assertEqual(expr._try_to_numeric(), 9*6*8)
+
     def test_evaluate_with_exact_rationals(self):
         expr = ExpressionScalar('1 / 3')
         self.assertEqual(TimeType.from_fraction(1, 3), expr.evaluate_with_exact_rationals({}))

tests/program/linspace_tests.py

@@ -14,7 +14,7 @@ def assert_vm_output_almost_equal(test: TestCase, expected, actual):
         test.assertEqual(t_e, t_a, f"Differing times in {idx} element")
         test.assertEqual(len(vals_e), len(vals_a), f"Differing channel count in {idx} element")
         for ch, (val_e, val_a) in enumerate(zip(vals_e, vals_a)):
-            test.assertAlmostEqual(val_e, val_a, msg=f"Differing values in {idx} element channel {ch}")
+            test.assertAlmostEqual(val_e, val_a, msg=f"Differing values in {idx} of {len(expected)} element channel {ch}")
 
 
 class SingleRampTest(TestCase):

tests/pulses/time_reversal_pulse_template_tests.py

@@ -7,10 +7,11 @@
 from qupulse.pulses.time_reversal_pulse_template import TimeReversalPulseTemplate
 from qupulse.utils.types import TimeType
 from qupulse.expressions import ExpressionScalar
-
+from qupulse.program.loop import LoopBuilder
+from qupulse.program.linspace import LinSpaceBuilder, LinSpaceVM, to_increment_commands
 from tests.pulses.sequencing_dummies import DummyPulseTemplate
 from tests.serialization_tests import SerializableTests
-
+from tests.program.linspace_tests import assert_vm_output_almost_equal
 
 class TimeReversalPulseTemplateTests(unittest.TestCase):
     def test_simple_properties(self):
@@ -29,19 +30,49 @@ def test_simple_properties(self):
 
         self.assertEqual(reversed_pt.identifier, 'reverse')
 
-    def test_time_reversal_program(self):
+    def test_time_reversal_loop(self):
         inner = ConstantPT(4, {'a': 3}) @ FunctionPT('sin(t)', 5, channel='a')
         manual_reverse = FunctionPT('sin(5 - t)', 5, channel='a') @ ConstantPT(4, {'a': 3})
         time_reversed = TimeReversalPulseTemplate(inner)
 
-        program = time_reversed.create_program()
-        manual_program = manual_reverse.create_program()
+        program = time_reversed.create_program(program_builder=LoopBuilder())
+        manual_program = manual_reverse.create_program(program_builder=LoopBuilder())
 
         t, data, _ = render(program, 9 / 10)
         _, manual_data, _ = render(manual_program, 9 / 10)
 
         np.testing.assert_allclose(data['a'], manual_data['a'])
 
+    def test_time_reversal_linspace(self):
+        constant_pt = ConstantPT(4, {'a': '3.0 + x * 1.0 + y * -0.3'})
+        function_pt = FunctionPT('sin(t)', 5, channel='a')
+        reversed_function_pt = function_pt.with_time_reversal()
+
+        inner = (constant_pt @ function_pt).with_iteration('x', 6)
+        inner_manual = (reversed_function_pt @ constant_pt).with_iteration('x', (5, -1, -1))
+
+        outer = inner.with_time_reversal().with_iteration('y', 8)
+        outer_man = inner_manual.with_iteration('y', 8)
+
+        self.assertEqual(outer.duration, outer_man.duration)
+
+        program = outer.create_program(program_builder=LinSpaceBuilder(channels=('a',)))
+        manual_program = outer_man.create_program(program_builder=LinSpaceBuilder(channels=('a',)))
+
+        commands = to_increment_commands(program)
+        manual_commands = to_increment_commands(manual_program)
+        self.assertEqual(commands, manual_commands)
+
+        manual_vm = LinSpaceVM(1)
+        manual_vm.set_commands(manual_commands)
+        manual_vm.run()
+
+        vm = LinSpaceVM(1)
+        vm.set_commands(commands)
+        vm.run()
+
+        assert_vm_output_almost_equal(self, manual_vm.history, vm.history)
+
 
 class TimeReversalPulseTemplateSerializationTests(unittest.TestCase, SerializableTests):
     @property