def testFpStr(self):
        # should give siz decimal places if less than 1.
        # if more, give up to seven sig figs
        from _rl_accel import fp_str
        assert fp_str(1,2,3)=='1 2 3'
        assert fp_str(1) == '1'

        assert fp_str(595.275574) == '595.2756'
        assert fp_str(59.5275574) == '59.52756'
        assert fp_str(5.95275574) == '5.952756'