# Smooth_AT — Creates a smoothed version of a cube.¶

This module defines the Smooth_AT class.

class admit.at.Smooth_AT.Smooth_AT(**keyval)[source]

Creates a smoothed version of a datacube.

Because interferometric arrays produce spectral cubes with the frequency varying along the spectral axis, these cubes have varying resolutions that are proportional to the wavelength. It is often desirable to smooth the resolution of the cube to a uniform one. In this task, we take an input cube, take the beam for each plane, compute the minimum ellipse that contains all the beams, and then smooth uniformly to that resolution. Also, we may wish to smooth along the velocity axis so that weak lines may come out more clearly in the resulting image. If the user desires, we take the input cube and smooth it to a given velocity resolution.

Keywords

bmaj: dictionary
A dictionary with keys ‘unit’ giving the unit of the major axis of the desired restoring beam and ‘value’, giving the value of the major axis of the desired restoring beam. If ‘value’ is negative, then the major axis of the restoring beam will be that of the minimum enclosing ellipse for all the beams in the image. Allowed units are “arcsec” and “pixel.” Default: {‘value’ : -1.0, ‘unit’: ‘arcsec’}.
bmin: dictionary
A dictionary with keys ‘unit’ giving the unit of the minor axis of the desired restoring beam and ‘value’, giving the value of the minor axis of the desired restoring beam. If ‘value’ is negative, then the minor axis of the restoring beam will be that of the minimum enclosing ellipse for all the beams in the image. Allowed units are “arcsec” and “pixel.” Default: {‘value’ : -1.0, ‘unit’: ‘arcsec’}.
bpa: float
A float that gives the position angle of the desired restoring beam. If negative, this will be set to the position angle of the minimum enclosing ellipse for all the beams in the image. Default: -1.0.
velres: dictionary
A dictionary with keys ‘unit’ giving the unit of the desired velocity resolution of the image cube and ‘value’, giving the value of the desired velocity resolution of the image cube. If ‘value’ is negative, no smoothing in velocity will be done. Allowed units are “m/s”, “km/s”, “Hz”, “kHz”,”MHz”, “GHz”, and “pixel” Default: {‘value’ : -1.0, ‘unit’: ‘km/s’}.

Input BDPs

SpwCube_BDP: count: varies
Input cubes; e.g., output from an Ingest_AT, ContinuumSub_AT or LineCube_AT.

Output BDPs

SpwCube_BDP: count: varies (equal to input count)
Smoothed cubes.
Parameters: keyval : dict, optional Dictionary of keyword:value pairs.

Attributes

 _version (string) Version ID string.

Methods

 addinput(item[, slot]) Add a BDP input to an AT. addinputbdp(item[, slot, insert]) Add a BDP to the _bdp_in list. addoutput(item[, slot]) Add a BDP output product to an AT. addoutputbdp(item[, slot, insert]) Add a BDP to the _bdp_out list. baseDir([path]) Get/set project base directory. bestMatch(at1, at2) Determines the better match of two tasks to the current one. checkfiles() Check if the files from all the BDP_out’s in an AT exist. checktype(item) Check the type of an object to see if it is a BDP. clearinput() Clear the input BDP list. clearoutput([delete]) Clear the output BDP list. copy() Creates an independent duplicate of the task. delete() Method to delete the AT and underlying BDPs. delinput(slot) Delete a specific BDP in the _bdp_in list. deloutput(slot) Delete a specific BDP in the _bdp_out list. dir([filename]) Absolute directory reference of the ADMIT project. dryrun() Method to do a dry run of the AT, generally just checks input values for errors. enabled([state]) Returns current task enabled setting, with optional reset. execute([args]) Executes the task. freeAlias(aliases[, alias]) Deletes alias reservation, if present. get(attrib) Method to get the given attributes value getProject() Retrieves project ID associated with the task. getVersion() Return the version string. getdtd(fl) Method to write out the dtd data. geteffectivelevel() Method to get the effective logging level of the logging subsystem getkey(key) Retrieval value for a key. getloggername() Method to get the name of the logger for this AT instance getlogginglevel() Method to get the current logging level of the AT haskey(key) Query if a key exists for an AT. html(inheader) Method to represent the current AT in HTML format. id([strip]) Returns task ID number. isAutoAlias([withEmpty, compat]) Whether the task alias appears to be auto-generated. isequal(at) Method to determine if two ATs are the same. isstale() Returns whether the AT is out of date. len2() Returns the length of _bdp_in and _bdp_out in a tuple. link() Increments the task link count. markChanged() Mark an AT that it’s state was changed, so it would need to be rerun. markUpToDate() Resets _stale to indicate that the AT does not need to be run. merge(at[, aliases]) Merges attributes from another task. mkdir(dirname) Make a directory in the ADMIT hierarchy. mkext(filename, ext[, alias]) Return a new filename with a new extension with optional ADMIT alias. newId(tid) Assigns the task a new ID number. reset(a) Performs an in-place shallow copy. run() The run method creates the BDP running([state]) Returns current task execution flag, with optional reset. save() Save (write) any BDPs connected to this AT. set(item, val) Method to set protected attributes, rather than direct access setAlias(aliases[, alias, auto]) Sets and registers the task alias, guaranteed unique among registered aliases. setProject(pid) Adds a project ID to task ID. set_bdp_in([bdpin]) Validate the _valid_bdp_in list and digest it into the appropriate attributes. set_bdp_out([bout]) Validate the _valid_bdp_out list and digest it into the appropriate attributes. seteffectivelevel(level) Method to set the effective logging level of the logging subsystem setkey([name, value, isinit]) Set keyword value. setloggername(name) Method to set the name of the logger for this AT instance setlogginglevel(level) Method to set the logging level show() Return the AT type. statusicons() return some html icons representing the enabled/stale status of this task summary() Returns the summary dictionary from the AT, for merging into the ADMIT Summary object. unlink() Decrements the task link count. userdata() Returns the user dictionary from the AT, for merging into the ADMIT userdata object. validateinput([describe]) Method to validate the _bdp_in’s against a dictionary of expected types. validatekeys() Method to error check all input keys. write(node) Method to write the AT to disk.
run()[source]

The run method creates the BDP

Parameters: None None
summary()[source]
Returns the summary dictionary from the AT, for merging
  Key      type        Description