pcdsdevices.pseudopos.LookupTablePositioner

class pcdsdevices.pseudopos.LookupTablePositioner(*args, table: ndarray, column_names: list[str], **kwargs)

A pseudo positioner which uses a look-up table to compute positions.

Currently supports 1 pseudo positioner and 1 “real” positioner, which should be columns of a 2D numpy.ndarray table.

For additional __init__ arguments, see ophyd.PseudoPositioner.

Parameters:

  • prefix (str) – The EPICS prefix of the real motor.

  • name (str) – A name to assign to this delay stage.

  • table (np.ndarray) – The table of information.

  • column_names (list of str) – List of column names, corresponding to the component attribute names. That is, if you have a real motor mtr = Cpt(EpicsMotor, ...), "mtr" should be in the list of column names of the table.

Methods

check_single(pseudo_single, single_pos)

Check if a new position for a single pseudo positioner is valid

configure(d: Dict[str, Any]) → Tuple[Dict[str, Any], Dict[str, Any]]

Configure the device for something during a run

This default implementation allows the user to change any of the configuration_attrs. Subclasses might override this to perform additional input validation, cleanup, etc.

Parameters:

d (dict) – The configuration dictionary. To specify the order that the changes should be made, use an OrderedDict.

Returns:

  • (old, new) tuple of dictionaries

  • Where old and new are pre- and post-configure configuration states.

describe() → OrderedDictType[str, Dict[str, Any]]

Provide schema and meta-data for read().

This keys in the OrderedDict this method returns must match the keys in the OrderedDict return by read().

This provides schema related information, (ex shape, dtype), the source (ex PV name), and if available, units, limits, precision etc.

Returns:

data_keys (OrderedDict) – The keys must be strings and the values must be dict-like with the event_model.event_descriptor.data_key schema.

forward(pseudo_pos: tuple) → tuple

Calculate a RealPosition from a given PseudoPosition

Must be defined on the subclass.

Parameters:

pseudo_pos (PseudoPosition) – The pseudo position input, a namedtuple.

Returns:

real_position (RealPosition) – The real position output, a namedtuple.

get(**kwargs)

Get the value of all components in the device

Keyword arguments are passed onto each signal.get(). Components beginning with an underscore will not be included.

inverse(real_pos: tuple) → tuple

Calculate a PseudoPosition from a given RealPosition

Must be defined on the subclass.

Parameters:

real_position (RealPosition) – The real position input

Returns:

pseudo_pos (PseudoPosition) – The pseudo position output

move(position, wait=True, timeout=None, moved_cb=None)

Move to a specified position, optionally waiting for motion to complete.

Parameters:

  • position – Pseudo position to move to.

  • moved_cb (callable) – Call this callback when movement has finished. This callback must accept one keyword argument: ‘obj’ which will be set to this positioner instance.

  • timeout (float, optional) – Maximum time to wait for the motion. If None, the default timeout for this positioner is used.

Returns:

status (MoveStatus)

Raises:
move_single(pseudo, position, **kwargs)

Move one PseudoSingle axis to a position

All other positioners will use their current setpoint/target value, if available. Failing that, their current readback value will be used (see PseudoSingle.sync and PseudoSingle.target).

Parameters:

  • pseudo (PseudoSingle) – PseudoSingle positioner to move

  • position (float) – Position only for the PseudoSingle

  • kwargs (dict) – Passed onto move

read() → OrderedDictType[str, Dict[str, Any]]

Read data from the device.

This method is expected to be as instantaneous as possible, with any substantial acquisition time taken care of in trigger().

The OrderedDict returned by this method must have identical keys (in the same order) as the OrderedDict returned by describe().

By convention, the first key in the return is the ‘primary’ key and maybe used by heuristics in bluesky.

The values in the ordered dictionary must be dict (-likes) with the keys {'value', 'timestamp'}. The 'value' may have any type, the timestamp must be a float UNIX epoch timestamp in UTC.

Returns:

data (OrderedDict) – The keys must be strings and the values must be dict-like with the keys {'value', 'timestamp'}

read_configuration() → OrderedDictType[str, Dict[str, Any]]

Dictionary mapping names to value dicts with keys: value, timestamp

To control which fields are included, change the Component kinds on the device, or modify the configuration_attrs list.

set(position, **kwargs)

Move to a new position asynchronously

Parameters:

position (PseudoPosition) – Position for the all of the pseudo axes

Returns:

status (MoveStatus)

set_current_position(position)

Adjust all offsets so that the pseudo position matches the input.

This will raise an AttributeError if any of the real motors is missing a set_current_position method.

Parameters:

position (PseudoPos) – The position

stop(success=False)

Stop the Device and all (instantiated) subdevices

summary()
to_pseudo_tuple(*args, **kwargs)

Convert arguments to a PseudoPosition namedtuple and kwargs

to_real_tuple(*args, **kwargs)

Convert arguments to a RealPosition namedtuple and kwargs

trigger() → StatusBase

Trigger the device and return status object.

This method is responsible for implementing ‘trigger’ or ‘acquire’ functionality of this device.

If there is an appreciable time between triggering the device and it being able to be read (via the read() method) then this method is also responsible for arranging that the StatusBase object returned by this method is notified when the device is ready to be read.

If there is no delay between triggering and being readable, then this method must return a StatusBase object which is already completed.

Returns:

status (StatusBase) – StatusBase object which will be marked as complete when the device is ready to be read.

Attributes

composite_egu

The composite engineering units (EGU) from all PseudoSingles

concurrent

If concurrent is set, motors will move concurrently (in parallel)

configuration_attrs
connected
egu

The engineering units (EGU) for positions

high_limit

All PseudoSingle high limits as a namedtuple

hints
kind
limits

All PseudoSingle limits as a namedtuple

low_limit

All PseudoSingle low limits as a namedtuple

moving
position

Pseudo motor position namedtuple

pseudo_positioners

Pseudo positioners instances in a namedtuple

Returns:

positioner_instances (PseudoPosition)

real_position

Real motor position namedtuple

real_positioners

Real positioners instances in a namedtuple

Returns:

positioner_instances (RealPosition)

sequential

If sequential is set, motors will move in the sequence they were defined in (i.e., in series)

settle_time

Amount of time to wait after moves to report status completion

subscriptions: ClassVar[FrozenSet[str]] = frozenset({'_req_done', 'acq_done', 'done_moving', 'readback', 'start_moving'})
target

Last commanded target positions

timeout

Amount of time to wait before to considering a motion as failed

table: ndarray
column_names: tuple[str, ...]