fplane – Focal plane

Base class for fplane file parsing and IFU.

This module provides a basic parser for the focal plane file and an object containing the informations about the IFU from the focal plane.

The focal plane is expected to be:

##IFUSLOT X_FP   Y_FP   SPECID SPECSLOT IFUID IFUROT PLATESC
  001     -450.0 150.0  37     42       024   0.0    1.00

Commented lines are ignored.

Use

The simplest use is to create a fplane instance passing the name of the focal plane file:

>>> fplane = FPlane("fplane.txt")  
>>> print(fplane.difus_ifuid)  
{'001': <pyhetdex.het.fplane.IFU object at 0x7ff6a493c1d0>,
'002': <pyhetdex.het.fplane.IFU object at 0x7ff6a493d1d0>, ...}

IFU Customisation

If you need to customise the IFU object, without changing the constructor signature, you can do something like this:

>>> class MyIFU(IFU):
...     def __init__(self, ifuslot, x, y, specid, specslot,
...                  ifuid, ifurot, platescl):
...         super(MyIFU, self).__init__(self, ifuslot, x, y, specid,
...                                     specslot, ifuid, ifurot, platescl)
...         # do something else
...     def new_method(self, a_variable):
...         # implement
...         pass
>>> fplane = FPlane("fplane.txt", ifu_class=MyIFU)

FPlane customisation

For more complex customisations, when you use a different way of storing the IFU informations, e.g. a list, a different __init__ signature, …, you can override the FPlane.add_ifu() method:

>>> class MyFPlane(FPlane):
...     def add_ifu(self, line):
...         # reimplement at need
...         pass

Implementation

class pyhetdex.het.fplane.IFU(ifuslot, x, y, specid, specslot, ifuid, ifurot, platescl)[source]

Contain the information for the IFU from the focal plane file.

The input type are cast to the corresponding types when initialising the object.

Parameters:
ifuslot : string

id of the ifu

x, y : float

x and y position of the ifu in the focal plane

specid : int

id of the spectrograph where the ifu is plugged into

specslot : int

id of the spectrograph slot where the spectrograph is plugged into

ifuid : string

id of the virus ifu bundle

ifurot : float

rotation of the IFU in its seat in the IHMP

platescl : float

focal plane plate scale at the position in the IHMP
Raises:
TypeError

if the ifuslot is not a string
Attributes:
ifuid, x, y, specid, specslot, ifuid, ifurot, platescl : as before
xid, yid : int

x (column) and y (row) id of the ifu in the ifu head mounting plate (IHMP), generated from the ifuslot
class pyhetdex.het.fplane.FPlane(fplane_file, ifu_class=<class 'pyhetdex.het.fplane.IFU'>, empty_specid='00', empty_ifuid='000', exclude_ifuslot=[], skip_empty=False)[source]

Focal plane.

Contains the dictionary of IFU instance (or derived or others), with the ifu id as key.

Parameters:
fplane_file : string

name of the file containing the ids and position of the IFUs

ifu_class : IFU instance (or anything else), optional

class definition containing the IFU information.

empty_specid, empty_ifuid : string, optional

if the entries for the SPECID (fourth column) or IFUID (sixt column) are as specified, they are replaced by a two digit negative number or a two digit number following a ‘N’. The number is increased any time one of the two conditions is met. Use it with caution as the SPECID and IFUID are used as dictionary keywords and should not be duplicated to avoid losing IFUs

exclude_ifuslot : list of string, optional

list of ifu slot ids to exclude when loading the fplane file. The ids must much exactly the string in the first column of the file

skip_empty : bool, optional

if True skip one ifu if the specid/ifuid is marked as empty
Attributes:
ifus

list of IFU instances

ifuids

list of IFUIDs (strings)

ifuslots

list of IFUSLOTs (strings)

specids

list of SPECIDs (integers)

difus_ifuid

dictionary of ifus; key: IFUID (string); value: IFU

difus_ifuslot

dictionary of ifus; key: IFUSLOT (string); value: IFU

difus_specid

dictionary of ifus; key: SPECID (int); value: IFU
_load_fplane(fname, empty_specid, empty_ifuid, exclude_ifuslot, skip_empty)[source]

Load the focal plane file and creates the IFU instances

Parameters:
fname : string

name of the focal plane file

empty_specid, empty_ifuid, exclude_ifuslot, skip_empty :

see FPlane
add_ifu(fpars)[source]

Parse a fplane line and add the IFU to the internal dictionary.

Make sure that the ifuid, specid are a three digit string. Override this method if the ifu class constructor is not as the one of IFU.

Parameters:
line : string

line of the fplane file
by_id(id_, idtype)[source]

Returns the ifu with id_

Parameters:
id_ : string

id of the spectrograph

idtype : str

type of the id; must be one of ‘ifuid’, ‘ifuslot’, ‘specid’
Returns:
:class:`IFU` instance
Raises:
NoIFUError

if there is no IFU identified by the input ID

UnknownIDTypeError

if the ID type is not known
by_ifuid(ifuid)[source]

Returns the ifu with ifuid

Parameters:
ifuid : string

id of the ifu
Returns:
:class:`IFU` instance
Raises:
NoIFUError

if there is no IFU identified by the input ID
by_ifuslot(ifuslot)[source]

Returns the ifu with ifuslot

Parameters:
ifuslot : string

id of the ihmp slot
Returns:
:class:`IFU` instance
Raises:
NoIFUError

if there is no IFU identified by the input ID
by_slotpos(x, y)[source]

Returns the ifu in ifu slot position x, y

Parameters:
x : int

x position in the IHMP (1 to 10)

y : int

y position in the IHMP (1 to 9)
Returns:
:class:`IFU` instance
Raises:
NoIFUError

if there is no IFU for the input positions
by_specid(specid)[source]

Returns the ifu with specid

Parameters:
specid : int or string

id of the spectrograph; the value is cast to an integer
Returns:
:class:`IFU` instance
Raises:
NoIFUError

if there is no IFU identified by the input ID

TypeError

if the input is not an int or a string that can be cast to an int
difus_ifuid

dictionary of ifus; key: IFUID (string); value: IFU instance

difus_ifuslot

dictionary of ifus; key: IFUSLOT (string); value: IFU instance

difus_specid

dictionary of ifus; key: SPECID (int); value: IFU instance

ifuids

list of IFUIDs (strings)

ifus

list of IFU instances

ifuslots

list of IFUSLOTs (strings)

specids

list of SPECIDs (integers)