def METHOD_NAME(inps):
    """Default output file name"""
    from mintpy.utils import readfile
    ftype = readfile.read_attribute(inps.file)['FILE_TYPE']
    fdir = os.path.dirname(inps.file)
    fbase = os.path.basename(inps.file)
    if ftype == 'ifgramStack':
        if inps.datasetName == 'coherence':
            inps.outfile = 'avgSpatialCoh.h5'
        elif 'unwrapPhase' in inps.datasetName:
            inps.outfile = 'avgPhaseVelocity.h5'
        else:
            inps.outfile = f'avg{inps.datasetName}.h5'
    elif ftype == 'timeseries':
        suffix = os.path.splitext(fbase)[0].split('timeseries')[1]
        inps.outfile = f'avgDisp{suffix}.h5'
    else:
        inps.outfile = f'avg{fbase}'
    inps.outfile = os.path.join(fdir, inps.outfile)
    print(f'output file: {inps.outfile}')
    return inps.outfile