Load family data updating the pheno_covar with  family ids found.

        :param pheno_covar: Phenotype/covariate object
        :return: None

def load_family_details(self, pheno_covar):
        """Load family data updating the pheno_covar with  family ids found.

        :param pheno_covar: Phenotype/covariate object
        :return: None
        """
        file = open(self.fam_details)
        header = file.readline()
        format = file.readline()
        self.file_index = 0

        mask_components = []        # 1s indicate an individual is to be masked out
        for line in file:
            words = line.strip().split()
            indid = ":".join(words[0:2])
            if DataParser.valid_indid(indid):
                mask_components.append(0)
                sex = int(words[5])
                pheno = float(words[6])
                pheno_covar.add_subject(indid, sex, pheno)
            else:
                mask_components.append(1)
        mask_components = numpy.array(mask_components)
        self.ind_mask = numpy.zeros(len(mask_components) * 2, dtype=numpy.int8).reshape(-1, 2)
        self.ind_mask[0:, 0] = mask_components
        self.ind_mask[0:, 1] = mask_components
        self.ind_count = self.ind_mask.shape[0]
        pheno_covar.freeze_subjects()