casa6

def commongrid(vis=[], spws=[], widths=[],

               outframe='LSRK', mode='channel', restfreqs=[], veltype='radio'):

​

    # DP (ESO), March 2015

​

    """

    commongrid: Determine the frequency grid with the maximum bandwidth

                which the SPWs of the same ID in the given MSs have in common

                and generate cvel code to produce MSs with identical grids

                with the given channel widths (and if velocity mode is used

                using the given rest frequencies).

​

                The generated cvel code will always used mode frequency.

​

                When successful, the return value will be a dictionary

                containing the necessary start, width, and nchan values,

                otherwise False.

​

    Parameters (similar to cvel and clean):

​

       vis - list of MSs

​

       spws - list of SPW IDs for which cvel code is to be generated

​

       widths - the new channels widths to be achieved in each of the SPWs;

                giving a single value assumes that value is to be used for all SPWs

​

       outframe - as in cvel

​

       mode - as in cvel

​

       restfreqs - (only needed for mode "velocity") the restfreq to be used for each SPW

​

       veltype - as in cvel

​

    """

​

    if len(vis)<2:

        print "ERROR: less than two input MSs"

        return False

​

    if type(widths)==int or type(widths)==str:

        widthlist = []

        for i in range(0,len(spws)):

            widthlist.append(widths)

        widths = widthlist

        print "# Expanding widths parameter to ", widths

​

    if len(spws)!=len(widths):

        print "ERROR: the lists in parameters spws and widths must have the same length"

        return False

​

    if mode=='velocity' and len(spws)!=len(restfreqs):

        print "ERROR: the lists in parameters spws and restfreqs must have the same length"

        return False

​

    mymst = mstool()

    grids = []

​

    try:

        for myms in vis:

            mymst.open(myms)

            grids.append([])