#! /usr/bin/env python

from openturns.testing import assert_almost_equal
from openturns.usecases import oscillator
import openturns as ot

"""
Test the Oscillator data class on a reference point.
"""
osc = oscillator.Oscillator()

assert_almost_equal(osc.model(osc.distribution.getMean()), [23.1897], 1e-2)

# Compute probability with FORM
model = osc.model
distribution = osc.distribution
vect = ot.RandomVector(distribution)
G = ot.CompositeRandomVector(model, vect)
event = ot.ThresholdEvent(G, ot.Less(), 0.0)
event.setName("failure")

optimAlgo = ot.Cobyla()
optimAlgo.setMaximumCallsNumber(1000)
optimAlgo.setMaximumAbsoluteError(1.0e-3)
optimAlgo.setMaximumRelativeError(1.0e-3)
optimAlgo.setMaximumResidualError(1.0e-3)
optimAlgo.setMaximumConstraintError(1.0e-3)

algo = ot.FORM(optimAlgo, event, distribution.getMean())
algo.run()
result = algo.getResult()

assert_almost_equal(result.getEventProbability(), 3.8906e-06, 1e-3)