casa6

# This program ...

# Copyright (C) 2013

# Associated Universities, Inc. Washington DC, USA.

#

# This program is free software; you can redistribute it and/or modify it

# under the terms of the GNU General Public License as published by the Free

# Software Foundation; either version 2 of the License, or (at your option)

# any later version.

#

# This program is distributed in the hope that it will be useful, but WITHOUT

# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

# more details.

#

# You should have received a copy of the GNU General Public License along

# with this program; if not, write to the Free Software Foundation, Inc.,

# 675 Massachusetts Ave, Cambridge, MA 02139, USA.

#

# Correspondence concerning AIPS++ should be addressed as follows:

#        Internet email: aips2-request@nrao.edu.

#        Postal address: AIPS++ Project Office

#                        National Radio Astronomy Observatory

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# $kgolap$

import dateutil

from datetime import datetime

import numpy as np

import pylab as pl

from casac import casac

qa=casac.quanta()

me=casac.measures()

def specframeconvert(val='344.84e9Hz',   inframe='TOPO', indoppler='RADIO', restfreq='1.410GHz', timebeg='2011/5/28/01h00m00', timeend='', direction='J2000 12h01m51 -18d52m00', observatory='VLA',  outframe='LSRK', npoints=100, doplot=False):

    """

    val= frequency or velocity quantity (e.g '113GHz' or '-25km/s')

    inframe=frame of input value (e.g 'TOPO', 'GEO', BARY')

    indoppler=doppler velocity definition if val is velocity ('RADIO', 'OPTICAL', 'Z' etc)

    restfrequency=line rest frequency if val is in velocity units

    timebeg=start of time range in UTC e.g '2012/12/25/00h00m00'

    timeend=end of time range in UTC or '' if only one value is needed

    direction=Source direction of interest (e.g 'J2000 12h01m51 -18d52m00')

    observatory=name of observatory to know where on earth this calculation is for

    outframe=frame of the output frequencies for the time range requested

    npoints= number of points to have values calculated in time range

    doplot=True or False (if Frequecy v/s Time plot is needed)

    """

    me.doframe(me.observatory(observatory))

    me.doframe(me.source(direction))

    me.doframe(me.epoch('utc', timebeg))

    epnow=me.epoch('utc', timebeg)

    interval=0

    xday=[]

    yday=[]

    if(timeend==''):

        npoints=1

    else:

        interval=qa.convert(qa.sub(qa.quantity(timeend), qa.quantity(timebeg)), 's')['value']

        interval=interval/npoints

​

    if ((qa.quantity(val)['unit'].find('Hz')) <0 and (qa.quantity(val)['unit'].find('m/s') >=0)):

        vel=me.doppler(indoppler, val)

        freq=me.tofrequency(inframe, vel, qa.quantity(restfreq))['m0']