def fiGroupFromLinkageGroup(matchArr, arrPos, groupId, timeKey, massKey):
    """ #TODO: docstring
    """
    fgi = Fgi(groupId)
    matchArr['isAnnotated'][arrPos]

    minT = numpy.min(matchArr[timeKey][arrPos])
    maxT = numpy.max(matchArr[timeKey][arrPos])
    minM = numpy.min(matchArr[massKey][arrPos])
    maxM = numpy.max(matchArr[massKey][arrPos])

    fgi.isValid = True
    fgi.specfiles = matchArr['specfile'][arrPos].tolist()
    fgi.featureIds = matchArr['id'][arrPos].tolist()
    fgi.isAnnotated = numpy.any(matchArr['isAnnotated'][arrPos])
    fgi.coordinates = ((minT, maxT), (minM, maxM))
    #fgi.clusterType = clusterType

    return fgi