import IMP.misc
import IMP
import IMP.test

class Tests(IMP.test.TestCase):
    """Tests for WLC unary function"""
    def test_wlc(self):
        """Test that decay has the right halflife"""
        m= IMP.Model()
        ps=[IMP.Particle(m) for i in range(0,100)]
        ap= []
        for i in range(0, len(ps)):
            for j in range(0,i):
                ap.append((ps[i], ps[j]))
        cf= IMP.core.CoinFlipPairPredicate(.9)
        dos= IMP.misc.DecayPairContainerOptimizerState(cf, ap, "decay")
        dos.set_log_level(IMP.base.TERSE)
        np= len(ap)
        dos.set_period(1)
        for i in range(0,6):
            dos.update()
        out= dos.get_output_container()
        nout= len(out.get_particle_pairs())
        # probabilistic
        self.assertAlmostEqual(nout, .53*np, delta=100)

if __name__ == '__main__':
    IMP.test.main()