def _calculate_similarity(c):
ma = {}<EOL>for idc in c:<EOL><INDENT>set1 = _get_seqs(c[idc])<EOL>[ma.update({(idc, idc2): _common(set1, _get_seqs(c[idc2]), idc, idc2)}) for idc2 in c if idc != idc2 and (idc2, idc) not in ma]<EOL><DEDENT>return ma<EOL>
Get a similarity matrix of % of shared sequence

    :param c: cluster object

    :return ma: similarity matrix