reading file with null model info

    nfile   File containing null model info

def readNullModelFile(nfile):
    """"
    reading file with null model info

    nfile   File containing null model info
    """

    params0_file = nfile+'.p0'
    nll0_file = nfile+'.nll0'
    assert os.path.exists(params0_file), '%s is missing.'%params0_file
    assert os.path.exists(nll0_file), '%s is missing.'%nll0_file
    params = SP.loadtxt(params0_file)
    NLL0 = SP.array([float(SP.loadtxt(nll0_file))])


    if params.ndim==1:
        rv = {'params0_g':SP.array([params[0]]),'params0_n':SP.array([params[1]]),'NLL0':NLL0}
    else:
        rv = {'params0_g':params[0],'params0_n':params[1],'NLL0':NLL0}

    return rv