Added possibility of assigning Parameter and ParameterVector by name

It is now possible to specify in the mapping the names of the parameters instead of the parameters themselves to assign parameters to pulse `Schedule`s and `ScheduleBlock`s. It is even possible to assign all the parameters of a ParameterVector by just specifying its name and setting as a value a list of parameter values.

qiskit/pulse/parameter_manager.py

@@ -54,7 +54,7 @@
 from copy import copy
 from typing import Any, Mapping, Sequence
 
-from qiskit.circuit import ParameterVector
+from qiskit.circuit.parametervector import ParameterVector, ParameterVectorElement
 from qiskit.circuit.parameter import Parameter
 from qiskit.circuit.parameterexpression import ParameterExpression, ParameterValueType
 from qiskit.pulse import instructions, channels
@@ -362,7 +362,8 @@ def assign_parameters(
         self,
         pulse_program: Any,
         value_dict: dict[
-            ParameterExpression | ParameterVector, ParameterValueType | Sequence[ParameterValueType]
+            ParameterExpression | ParameterVector | str,
+            ParameterValueType | Sequence[ParameterValueType],
         ],
     ) -> Any:
         """Modify and return program data with parameters assigned according to the input.
@@ -397,7 +398,7 @@ def update_parameter_table(self, new_node: Any):
     def _unroll_param_dict(
         self,
         parameter_binds: Mapping[
-            Parameter | ParameterVector, ParameterValueType | Sequence[ParameterValueType]
+            Parameter | ParameterVector | str, ParameterValueType | Sequence[ParameterValueType]
         ],
     ) -> Mapping[Parameter, ParameterValueType]:
         """
@@ -415,7 +416,7 @@ def _unroll_param_dict(
                 if not isinstance(value, Sequence):
                     raise PulseError(
                         f"Parameter vector '{parameter.name}' has length {len(parameter)},"
-                        f" but was assigned to a single value."
+                        f" but was assigned to {value}."
                     )
                 if len(parameter) != len(value):
                     raise PulseError(
@@ -424,7 +425,24 @@ def _unroll_param_dict(
                     )
                 out.update(zip(parameter, value))
             elif isinstance(parameter, str):
-                out[self.get_parameters(parameter)] = value
+                for param in self.parameters:
+                    if param.name == parameter:
+                        out[param] = value
+                    elif (
+                        isinstance(param, ParameterVectorElement) and param.vector.name == parameter
+                    ):
+                        if not isinstance(value, Sequence):
+                            raise PulseError(
+                                f"ParameterVector '{param.vector.name}' has length {len(param.vector)},"
+                                f" but was assigned to a single value."
+                            )
+                        if len(param.vector) != len(value):
+                            raise PulseError(
+                                f"ParameterVector '{param.vector.name}' has length {len(param.vector)},"
+                                f" but was assigned to {len(value)} values."
+                            )
+                        out[param] = value[param.index]
+
             else:
                 out[parameter] = value
         return out

qiskit/pulse/schedule.py

@@ -714,16 +714,17 @@ def is_parameterized(self) -> bool:
     def assign_parameters(
         self,
         value_dict: dict[
-            ParameterExpression | ParameterVector, ParameterValueType | Sequence[ParameterValueType]
+            ParameterExpression | ParameterVector | str,
+            ParameterValueType | Sequence[ParameterValueType],
         ],
         inplace: bool = True,
     ) -> "Schedule":
         """Assign the parameters in this schedule according to the input.
 
         Args:
-            value_dict: A mapping from parameters (parameter vectors) to either
-            numeric values (list of numeric values)
-            or another Parameter expression (list of Parameter expressions).
+            value_dict: A mapping from parameters or parameter names (parameter vector
+            or parameter vector name) to either numeric values (list of numeric values)
+            or another parameter expression (list of parameter expressions).
             inplace: Set ``True`` to override this instance with new parameter.
 
         Returns:
@@ -1415,15 +1416,16 @@ def is_referenced(self) -> bool:
     def assign_parameters(
         self,
         value_dict: dict[
-            ParameterExpression | ParameterVector, ParameterValueType | Sequence[ParameterValueType]
+            ParameterExpression | ParameterVector | str,
+            ParameterValueType | Sequence[ParameterValueType],
         ],
         inplace: bool = True,
     ) -> "ScheduleBlock":
         """Assign the parameters in this schedule according to the input.
 
         Args:
-            value_dict: A mapping from parameters (parameter vectors) to either numeric values
-            (list of numeric values)
+            value_dict: A mapping from parameters or parameter names (parameter vector
+            or parameter vector name) to either numeric values (list of numeric values)
             or another parameter expression (list of parameter expressions).
             inplace: Set ``True`` to override this instance with new parameter.
 

releasenotes/notes/parameter_assignment_by_name_for_pulse_schedules-3a27bbbbf235fb9e.yaml

@@ -0,0 +1,10 @@
+---
+prelude: >
+
+features_pulse:
+  - |
+    It is now possible to assign parameters to pulse `Schedule`and `ScheduleBlock` objects by specifying
+    the parameter name as a string. The parameter name can be used to assign values to all parameters within the
+    `Schedule` or `ScheduleBlock` that have the same name. Moreover, the parameter name of a `ParameterVector`
+    can be used to assign all values of the vector simultaneously (the list of values should therefore match the
+    length of the vector).

test/python/pulse/test_parameter_manager.py

@@ -515,6 +515,42 @@ def test_parametric_pulses_with_parameter_vector(self):
         self.assertEqual(sched2.instructions[0][1].pulse.sigma, 4.0)
         self.assertEqual(sched2.instructions[1][1].phase, 0.1)
 
+    def test_pulse_assignment_with_parameter_names(self):
+        """Test pulse assignment with parameter names."""
+        sigma = Parameter("sigma")
+        amp = Parameter("amp")
+        param_vec = ParameterVector("param_vec", 2)
+
+        waveform = pulse.library.Gaussian(duration=128, sigma=sigma, amp=amp)
+        waveform2 = pulse.library.Gaussian(duration=128, sigma=40, amp=amp)
+        block = pulse.ScheduleBlock()
+        block += pulse.Play(waveform, pulse.DriveChannel(10))
+        block += pulse.Play(waveform2, pulse.DriveChannel(10))
+        block += pulse.ShiftPhase(param_vec[0], pulse.DriveChannel(10))
+        block += pulse.ShiftPhase(param_vec[1], pulse.DriveChannel(10))
+        block.assign_parameters({"amp": 0.2, "sigma": 4, "param_vec": [3.14, 1.57]}, inplace=True)
+
+        self.assertEqual(block.blocks[0].pulse.amp, 0.2)
+        self.assertEqual(block.blocks[0].pulse.sigma, 4.0)
+        self.assertEqual(block.blocks[1].pulse.amp, 0.2)
+        self.assertEqual(block.blocks[2].phase, 3.14)
+        self.assertEqual(block.blocks[3].phase, 1.57)
+
+        sched = pulse.Schedule()
+        sched += pulse.Play(waveform, pulse.DriveChannel(10))
+        sched += pulse.Play(waveform2, pulse.DriveChannel(10))
+        sched += pulse.ShiftPhase(param_vec[0], pulse.DriveChannel(10))
+        sched += pulse.ShiftPhase(param_vec[1], pulse.DriveChannel(10))
+        sched1 = sched.assign_parameters(
+            {"amp": 0.2, "sigma": 4, "param_vec": [3.14, 1.57]}, inplace=False
+        )
+
+        self.assertEqual(sched1.instructions[0][1].pulse.amp, 0.2)
+        self.assertEqual(sched1.instructions[0][1].pulse.sigma, 4.0)
+        self.assertEqual(sched1.instructions[1][1].pulse.amp, 0.2)
+        self.assertEqual(sched1.instructions[2][1].phase, 3.14)
+        self.assertEqual(sched1.instructions[3][1].phase, 1.57)
+
 
 class TestScheduleTimeslots(QiskitTestCase):
     """Test for edge cases of timing overlap on parametrized channels.