def float_list_string(vals, nchar=7, ndec=3, nspaces=2, mesg='', left=False):
    """return a string to display the floats:
        vals    : the list of float values
        nchar   : [7] number of characters to display per float
        ndec    : [3] number of decimal places to print to
        nspaces : [2] number of spaces between each float
   """
    if left:
        format = '%-*.*f%*s'
    else:
        format = '%*.*f%*s'
    istr = mesg
    for val in vals:
        istr += format % (nchar, ndec, val, nspaces, '')
    return istr
