|
|||
NRAO Home > CASA > CASA Task Reference Manual |
|
0.1.111 sdmathold
Requires:
Synopsis
ASAP SD task [DEPRECATED]: simple arithmetic of spectra
Description
### DEPRECATION WARNING
#################################################
This task will be removed in CASA 5.1. The functionality of this task with
CASA image format is replicated with immath.
#########################################################################
Task sdmathold execute a simple arithmetic (i.e., subtraction, addition, multiplication, and division) expression for single dish spectra. The spectral data file can be any of the formats supported by ASAP (scantable, MS, rpfits, and SDFITS). In the expression, these file names should be put inside of single or double quotes.
You can use variables in the expression. If you want to use, you must define
varnames dictionary. Name of variables should be simple, e.g. V0, V1, etc., to
avoid unexpected error. Keys of varnames must be name of variables that you
used in the expression, and their values will be substituted for variables in the
expression. Allowed type for the value is numerical values, one- or
two-dimensional lists (Python list or numpy.ndarray), and filename strings that
indicate spectral data or ASCII text, which is space-separated list of numerical
values consisting of adequate number of rows and columns. In case you give a
list of file names in infiles, they are automatically referred to as IN0, IN1, etc.
in expr and you can not use IN0, IN1, etc. as variable names in varnames.
Arguments
Inputs |
| ||
infiles |
| a list of names of input SD datasets
| |
| allowed: | stringArray |
|
| Default: |
| |
expr |
| mathematical expression using spectra
| |
| allowed: | string |
|
| Default: |
| |
varnames |
| dictionary of variables and their values used in expr
| |
| allowed: | any |
|
| Default: | variant |
|
antenna |
| select an antenna name or ID, e.g. ’PM03’ (only effective
for MS input)
| |
| allowed: | any |
|
| Default: | variant 0 |
|
fluxunit |
| units of the flux (”=current)
| |
| allowed: | string |
|
| Default: |
|
|
telescopeparam |
| parameters of telescope for flux conversion (see examples
in help)
| |
| allowed: | any |
|
| Default: | variant
|
|
field |
| select data by field IDs and names, e.g. ’3C2*’ (”=all)
| |
| allowed: | string |
|
| Default: |
|
|
spw |
| select data by IF IDs (spectral windows), e.g. ’3,5,7’
(”=all)
| |
| allowed: | string |
|
| Default: |
|
|
scan |
| select data by scan numbers, e.g. ’21~23’ (”=all)
| |
| allowed: | string |
|
| Default: |
|
|
pol |
| select data by polarization IDs, e.g. ’0,1’ (”=all)
| |
| allowed: | string |
|
| Default: |
|
|
outfile |
| name of output file (must be specified)
| |
| allowed: | string |
|
| Default: |
|
|
outform |
| output file format (See a WARNING in help)
| |
| allowed: | string |
|
| Default: | ASAP |
|
overwrite |
| overwrite the output file if already exists [True, False]
| |
| allowed: | bool |
|
| Default: | False |
|
void
Example
Keyword arguments:
infiles -- a list of names of input SD datasets
The file names will automatically replace the phrases
IN0, IN1, ... in expr parameter.
expr -- mathematical expression using scantables
varnames -- a python dictionary of variables in expr and their values.
Keys must be coincide with variables used in expr.
Values are substituted in each value in expr.
antenna -- select an antenna name or ID
default: 0
example: ’PM03’
NOTE this parameter is effective only for MS input
fluxunit -- units for line flux
options: ’K’,’Jy’,’’
default: ’’ (keep current fluxunit in data)
WARNING: For GBT data, see description below.
>>> fluxunit expandable parameter
telescopeparam -- parameters of telescope for flux conversion
options: (str) name or (list) list of gain info
default: ’’ (none set)
example: if telescopeparam=’’, it tries to get the telescope
name from the data.
Full antenna parameters (diameter,ap.eff.) known
to ASAP are
’ATPKSMB’, ’ATPKSHOH’, ’ATMOPRA’, ’DSS-43’,
’CEDUNA’,’HOBART’. For GBT, it fixes default fluxunit
to ’K’ first then convert to a new fluxunit.
telescopeparam=[104.9,0.43] diameter(m), ap.eff.
telescopeparam=[0.743] gain in Jy/K
telescopeparam=’FIX’ to change default fluxunit
see description below
field -- select data by field IDs and names
default: ’’ (use all fields)
example: field=’3C2*’ (all names starting with 3C2)
field=’0,4,5~7’ (field IDs 0,4,5,6,7)
field=’0,3C273’ (field ID 0 or field named 3C273)
this selection is in addition to the other selections to data
spw -- select data by IF IDs (spectral windows)
NOTE this task only supports IF ID selction and ignores channel
selection.
default: ’’ (use all IFs and channels)
example: spw=’3,5,7’ (IF IDs 3,5,7; all channels)
spw=’<2’ (IF IDs less than 2, i.e., 0,1; all channels)
spw=’30~45GHz’ (IF IDs with the center frequencies in range 30-45GHz; all channels)
this selection is in addition to the other selections to data
scan -- select data by scan numbers
default: ’’ (use all scans)
example: scan=’21~23’ (scan IDs 21,22,23)
this selection is in addition to the other selections to data
pol -- select data by polarization IDs
default: ’’ (use all polarizations)
example: pol=’0,1’ (polarization IDs 0,1)
this selection is in addition to the other selections to data
outfile -- name of output file
default: ’’ (must be specified)
outform -- output file format
options: ’ASAP’,’MS2’, ’ASCII’,’SDFITS’
default: ’ASAP’
NOTE the ASAP format is easiest for further sd
processing; use MS2 for CASA imaging.
If ASCII, then will append some stuff to
the outfile name
overwrite -- overwrite the output file if already exists
options: (bool) True,False
default: False
NOTE this parameter is ignored when outform=’ASCII’
DESCRIPTION:
Task sdmathold execute a simple arithmetic (i.e., subtraction, addition,
multiplication, and division) expression for single dish spectra.
The spectral data file can be any of the formats supported by
ASAP (scantable, MS, rpfits, and SDFITS). In the expression,
these file names should be put inside of single or double quotes.
You can use variables in the expression. If you want to use, you
must define varnames dictionary. Name of variables should be simple,
e.g. V0, V1, etc., to avoid unexpected error. Keys of varnames must
be name of variables that you used in the expression, and their
values will be substituted for variables in the expression. Allowed
type for the value is numerical values, one- or two-dimensional lists
(Python list or numpy.ndarray), and filename strings that indicate
spectral data or ASCII text, which is space-separated list of
numerical values consisting of adequate number of rows and columns.
In case you give a list of file names in infiles, they are
automatically referred to as IN0, IN1, etc. in expr and you can not
use IN0, IN1, etc. as variable names in varnames.
The fluxunit can be set, otherwise, the current settings of the first
spectral data in the expression are used.
Other selections (e.g. scan No, . IF, Pol) also apply to all
the spectral data in the expression, so if any of the data does
not contains selection, the task will produce no output.
WARNING for the GBT raw SDFITS format data as input:
SDtasks are able to handle GBT raw SDFITS format data since the
data filler is available. However, the functionality is not well
tested yet, so that there may be unknown bugs.
Example:
# do on-off/off calculation
expr=’("orion_on_data.asap"-"orion_off_data.asap")/"orion_off_data.asap"
outfile=’orion_cal.asap’
sdmathold()
# do on-off/off calculation (using infiles)
infiles = ["orion_on_data.asap", "orion_off_data.asap"]
expr=’(IN0-IN1)/IN1’
outfile=’orion_cal.asap’
sdmathold()
# do on-off/off calculation using varnames
varnames={} (this can be skipped if you executed inp(sdmathold) or
default(sdmathold).)
varnames[’V0’]="orion_on_data.asap"
varnames[’V1’]="orion_off_data.asap"
varnames[’V2’]=1.0
expr=’V0/V1-V2’
outfile=’orion_cal.asap’
sdmathold()
# do on-off/off calculation using varnames (in pythonic way)
sdmathold(varnames={’V0’:’orion_on_data.asap’,’V1’:’orion_off_data.asap’,
’V2’:1.0}, expr=’V0/V1-V2’, outfile=’orion_cal.asap’)
# interpretation of ASCII file value for varnames
If the contents of input ASCII file is shown as,
0.5 0.3 0.2
1.0 0.2 0.9
it is interpreted as a list [[0.5, 0.3, 0.2],[1.0, 0.2, 0.9]].
More information about CASA may be found at the
CASA web page
Copyright © 2016 Associated Universities Inc., Washington, D.C.
This code is available under the terms of the GNU General Public Lincense
Home |
Contact Us |
Directories |
Site Map |
Help |
Privacy Policy |
Search