# Copyright (c) 2014, Alan Saul
# Licensed under the BSD 3-clause license (see LICENSE.txt)
import numpy as np
import unittest
import GPy
from GPy.models import GradientChecker
import functools
import inspect
from GPy.likelihoods import link_functions
from functools import partial
fixed_seed = 7

#np.seterr(divide='raise')
def dparam_partial(inst_func, *args):
    """
    If we have a instance method that needs to be called but that doesn't
    take the parameter we wish to change to checkgrad, then this function
    will change the variable using set params.

    inst_func: should be a instance function of an object that we would like
                to change
    param: the param that will be given to set_params
    args: anything else that needs to be given to the function (for example
          the f or Y that are being used in the function whilst we tweak the
          param
    """
    def param_func(param_val, param_name, inst_func, args):
        #inst_func.__self__._set_params(param)
        #inst_func.__self__.add_parameter(Param(param_name, param_val))
        inst_func.__self__[param_name] = param_val
        return inst_func(*args)
    return functools.partial(param_func, inst_func=inst_func, args=args)

def dparam_checkgrad(func, dfunc, params, params_names, args, constraints=None, randomize=False, verbose=False):
    """
    checkgrad expects a f: R^N -> R^1 and df: R^N -> R^N
    However if we are holding other parameters fixed and moving something else
    We need to check the gradient of each of the fixed parameters
    (f and y for example) seperately,  whilst moving another parameter.
    Otherwise f: gives back R^N and
              df: gives back R^NxM where M is
    The number of parameters and N is the number of data
    Need to take a slice out from f and a slice out of df
    """
    print("\n{} likelihood: {} vs {}".format(func.__self__.__class__.__name__,
                                           func.__name__, dfunc.__name__))
    partial_f = dparam_partial(func, *args)
    partial_df = dparam_partial(dfunc, *args)
    gradchecking = True
    zipped_params = zip(params, params_names)
    for param_ind, (param_val, param_name) in enumerate(zipped_params):
        #Check one parameter at a time, make sure it is 2d (as some gradients only return arrays) then strip out the parameter
        f_ = partial_f(param_val, param_name)
        df_ = partial_df(param_val, param_name)
        #Reshape it such that we have a 3d matrix incase, that is we want it (?, N, D) regardless of whether ? is num_params or not
        f_ = f_.reshape(-1, f_.shape[0], f_.shape[1])
        df_ = df_.reshape(-1, f_.shape[0], f_.shape[1])

        #Get the number of f and number of dimensions
        fnum = f_.shape[-2]
        fdim = f_.shape[-1]
        dfnum = df_.shape[-2]

        for fixed_val in range(dfnum):
            #dlik and dlik_dvar gives back 1 value for each
            f_ind = min(fnum, fixed_val+1) - 1
            print("fnum: {} dfnum: {} f_ind: {} fixed_val: {}".format(fnum, dfnum, f_ind, fixed_val))
            #Make grad checker with this param moving, note that set_params is NOT being called
            #The parameter is being set directly with __setattr__
            #Check only the parameter and function value we wish to check at a time
            #func = lambda p_val, fnum, fdim, param_ind, f_ind, param_ind: partial_f(p_val, param_name).reshape(-1, fnum, fdim)[param_ind, f_ind, :]
            #dfunc_dparam = lambda d_val, fnum, fdim, param_ind, fixed_val: partial_df(d_val, param_name).reshape(-1, fnum, fdim)[param_ind, fixed_val, :]

            #First we reshape the output such that it is (num_params, N, D) then we pull out the relavent parameter-findex and checkgrad just this index at a time
            func = lambda p_val: partial_f(p_val, param_name).reshape(-1, fnum, fdim)[param_ind, f_ind, :]
            dfunc_dparam = lambda d_val: partial_df(d_val, param_name).reshape(-1, fnum, fdim)[param_ind, fixed_val, :]
            grad = GradientChecker(func, dfunc_dparam, param_val, [param_name])

            if constraints is not None:
                for constrain_param, constraint in constraints:
                    if grad.grep_param_names(constrain_param):
                        constraint(constrain_param, grad)
                    else:
                        print("parameter didn't exist")
                    print(constrain_param, " ", constraint)
            if randomize:
                grad.randomize()
            if verbose:
                print(grad)
                grad.checkgrad(verbose=1)
            if not grad.checkgrad(verbose=True):
                gradchecking = False

            if not grad.checkgrad(verbose=True):
                gradchecking = False

    return gradchecking


from nose.tools import with_setup
class TestNoiseModels(object):
    """
    Generic model checker
    """
    def setUp(self):
        np.random.seed(fixed_seed)
        self.N = 15
        self.D = 3
        self.X = np.random.rand(self.N, self.D)*10

        self.real_std = 0.1
        noise = np.random.randn(*self.X[:, 0].shape)*self.real_std
        self.Y = (np.sin(self.X[:, 0]*2*np.pi) + noise)[:, None]
        self.f = np.random.rand(self.N, 1)
        self.binary_Y = np.asarray(np.random.rand(self.N) > 0.5, dtype=np.int)[:, None]
        self.positive_Y = np.exp(self.Y.copy())
        tmp = np.round(self.X[:, 0]*3-3)[:, None] + np.random.randint(0,3, self.X.shape[0])[:, None]
        self.integer_Y = np.where(tmp > 0, tmp, 0)

        self.var = 0.2
        self.deg_free = 4.0

        #Make a bigger step as lower bound can be quite curved
        self.step = 1e-4

        """
        Dictionary where we nest models we would like to check
            Name: {
                "model": model_instance,
                "grad_params": {
                    "names": [names_of_params_we_want, to_grad_check],
                    "vals": [values_of_params, to_start_at],
                    "constrain": [constraint_wrappers, listed_here]
                    },
                "laplace": boolean_of_whether_model_should_work_for_laplace,
                "ep": boolean_of_whether_model_should_work_for_laplace,
                "link_f_constraints": [constraint_wrappers, listed_here]
                }
        """
        self.noise_models = {"Student_t_default": {
            "model": GPy.likelihoods.StudentT(deg_free=self.deg_free, sigma2=self.var),
            "grad_params": {
                "names": [".*t_scale2"],
                "vals": [self.var],
                "constraints": [(".*t_scale2", self.constrain_positive), (".*deg_free", self.constrain_fixed)]
            },
            "laplace": True
            },
            #"Student_t_deg_free": {
                #"model": GPy.likelihoods.StudentT(deg_free=self.deg_free, sigma2=self.var),
                #"grad_params": {
                    #"names": [".*deg_free"],
                    #"vals": [self.deg_free],
                    #"constraints": [(".*t_scale2", self.constrain_fixed), (".*deg_free", self.constrain_positive)]
                #},
                #"laplace": True
            #},
            "Student_t_1_var": {
                "model": GPy.likelihoods.StudentT(deg_free=self.deg_free, sigma2=self.var),
                "grad_params": {
                    "names": [".*t_scale2"],
                    "vals": [1.0],
                    "constraints": [(".*t_scale2", self.constrain_positive), (".*deg_free", self.constrain_fixed)]
                },
                "laplace": True
            },
            "Student_t_small_deg_free": {
                "model": GPy.likelihoods.StudentT(deg_free=1.5, sigma2=self.var),
                "grad_params": {
                    "names": [".*t_scale2"],
                    "vals": [self.var],
                    "constraints": [(".*t_scale2", self.constrain_positive), (".*deg_free", self.constrain_fixed)]
                },
                "laplace": True
            },
            "Student_t_small_var": {
                "model": GPy.likelihoods.StudentT(deg_free=self.deg_free, sigma2=self.var),
                "grad_params": {
                    "names": [".*t_scale2"],
                    "vals": [0.001],
                    "constraints": [(".*t_scale2", self.constrain_positive), (".*deg_free", self.constrain_fixed)]
                },
                "laplace": True
            },
            "Student_t_large_var": {
                "model": GPy.likelihoods.StudentT(deg_free=self.deg_free, sigma2=self.var),
                "grad_params": {
                    "names": [".*t_scale2"],
                    "vals": [10.0],
                    "constraints": [(".*t_scale2", self.constrain_positive), (".*deg_free", self.constrain_fixed)]
                },
                "laplace": True
            },
            "Student_t_approx_gauss": {
                "model": GPy.likelihoods.StudentT(deg_free=1000, sigma2=self.var),
                "grad_params": {
                    "names": [".*t_scale2"],
                    "vals": [self.var],
                    "constraints": [(".*t_scale2", self.constrain_positive), (".*deg_free", self.constrain_fixed)]
                },
                "laplace": True
            },
            #"Student_t_log": {
            #"model": GPy.likelihoods.StudentT(gp_link=link_functions.Log(), deg_free=5, sigma2=self.var),
            #"grad_params": {
            #"names": [".*t_noise"],
            #"vals": [self.var],
            #"constraints": [(".*t_noise", self.constrain_positive), (".*deg_free", self.constrain_fixed)]
            #},
            #"laplace": True
            #},
            "Gaussian_default": {
                "model": GPy.likelihoods.Gaussian(variance=self.var),
                "grad_params": {
                    "names": [".*variance"],
                    "vals": [self.var],
                    "constraints": [(".*variance", self.constrain_positive)]
                },
                "laplace": True,
                "ep": False, # FIXME: Should be True when we have it working again
                "variational_expectations": True,
            },
            "Gaussian_log": {
                "model": GPy.likelihoods.Gaussian(gp_link=link_functions.Log(), variance=self.var),
                "grad_params": {
                    "names": [".*variance"],
                    "vals": [self.var],
                    "constraints": [(".*variance", self.constrain_positive)]
                },
                "laplace": True,
                "variational_expectations": True
            },
            #"Gaussian_probit": {
            #"model": GPy.likelihoods.gaussian(gp_link=link_functions.Probit(), variance=self.var, D=self.D, N=self.N),
            #"grad_params": {
            #"names": ["noise_model_variance"],
            #"vals": [self.var],
            #"constraints": [constrain_positive]
            #},
            #"laplace": True
            #},
            #"Gaussian_log_ex": {
            #"model": GPy.likelihoods.gaussian(gp_link=link_functions.Log_ex_1(), variance=self.var, D=self.D, N=self.N),
            #"grad_params": {
            #"names": ["noise_model_variance"],
            #"vals": [self.var],
            #"constraints": [constrain_positive]
            #},
            #"laplace": True
            #},
            "Bernoulli_default": {
                "model": GPy.likelihoods.Bernoulli(),
                "link_f_constraints": [partial(self.constrain_bounded, lower=0, upper=1)],
                "laplace": True,
                "Y": self.binary_Y,
                "ep": False, # FIXME: Should be True when we have it working again
                "variational_expectations": True
            },
            "Exponential_default": {
                "model": GPy.likelihoods.Exponential(),
                "link_f_constraints": [self.constrain_positive],
                "Y": self.positive_Y,
                "laplace": True,
            },
            "Poisson_default": {
                "model": GPy.likelihoods.Poisson(),
                "link_f_constraints": [self.constrain_positive],
                "Y": self.integer_Y,
                "laplace": True,
                "ep": False #Should work though...
            },
            #,
            #GAMMA needs some work!"Gamma_default": {
            #"model": GPy.likelihoods.Gamma(),
            #"link_f_constraints": [constrain_positive],
            #"Y": self.positive_Y,
            #"laplace": True
            #}
        }


    ####################################################
    # Constraint wrappers so we can just list them off #
    ####################################################
    def constrain_fixed(self, regex, model):
        model[regex].constrain_fixed()

    def constrain_negative(self, regex, model):
        model[regex].constrain_negative()

    def constrain_positive(self, regex, model):
        model[regex].constrain_positive()

    def constrain_fixed_below(self, regex, model, up_to):
        model[regex][0:up_to].constrain_fixed()

    def constrain_fixed_above(self, regex, model, above):
        model[regex][above:].constrain_fixed()

    def constrain_bounded(self, regex, model, lower, upper):
        """
        Used like: partial(constrain_bounded, lower=0, upper=1)
        """
        model[regex].constrain_bounded(lower, upper)


    def tearDown(self):
        self.Y = None
        self.f = None
        self.X = None

    def test_scale2_models(self):
        self.setUp()

        for name, attributes in self.noise_models.items():
            model = attributes["model"]
            if "grad_params" in attributes:
                params = attributes["grad_params"]
                param_vals = params["vals"]
                param_names= params["names"]
                param_constraints = params["constraints"]
            else:
                params = []
                param_vals = []
                param_names = []
                constrain_positive = []
                param_constraints = []
            if "link_f_constraints" in attributes:
                link_f_constraints = attributes["link_f_constraints"]
            else:
                link_f_constraints = []
            if "Y" in attributes:
                Y = attributes["Y"].copy()
            else:
                Y = self.Y.copy()
            if "f" in attributes:
                f = attributes["f"].copy()
            else:
                f = self.f.copy()
            if "Y_metadata" in attributes:
                Y_metadata = attributes["Y_metadata"].copy()
            else:
                Y_metadata = None
            if "laplace" in attributes:
                laplace = attributes["laplace"]
            else:
                laplace = False
            if "ep" in attributes:
                ep = attributes["ep"]
            else:
                ep = False
            if "variational_expectations" in attributes:
                var_exp = attributes["variational_expectations"]
            else:
                var_exp = False

            #if len(param_vals) > 1:
                #raise NotImplementedError("Cannot support multiple params in likelihood yet!")

            #Required by all
            #Normal derivatives
            yield self.t_logpdf, model, Y, f, Y_metadata
            yield self.t_dlogpdf_df, model, Y, f, Y_metadata
            yield self.t_d2logpdf_df2, model, Y, f, Y_metadata
            #Link derivatives
            yield self.t_dlogpdf_dlink, model, Y, f, Y_metadata, link_f_constraints
            yield self.t_d2logpdf_dlink2, model, Y, f, Y_metadata, link_f_constraints
            if laplace:
                #Laplace only derivatives
                yield self.t_d3logpdf_df3, model, Y, f, Y_metadata
                yield self.t_d3logpdf_dlink3, model, Y, f, Y_metadata, link_f_constraints
                #Params
                yield self.t_dlogpdf_dparams, model, Y, f, Y_metadata, param_vals, param_names, param_constraints
                yield self.t_dlogpdf_df_dparams, model, Y, f, Y_metadata, param_vals, param_names, param_constraints
                yield self.t_d2logpdf2_df2_dparams, model, Y, f, Y_metadata, param_vals, param_names, param_constraints
                #Link params
                yield self.t_dlogpdf_link_dparams, model, Y, f, Y_metadata, param_vals, param_names, param_constraints
                yield self.t_dlogpdf_dlink_dparams, model, Y, f, Y_metadata, param_vals, param_names, param_constraints
                yield self.t_d2logpdf2_dlink2_dparams, model, Y, f, Y_metadata, param_vals, param_names, param_constraints

                #laplace likelihood gradcheck
                yield self.t_laplace_fit_rbf_white, model, self.X, Y, f, Y_metadata, self.step, param_vals, param_names, param_constraints
            if ep:
                #ep likelihood gradcheck
                yield self.t_ep_fit_rbf_white, model, self.X, Y, f, Y_metadata, self.step, param_vals, param_names, param_constraints
            if var_exp:
                #Need to specify mu and var!
                yield self.t_varexp, model, Y, Y_metadata
                yield self.t_dexp_dmu, model, Y, Y_metadata
                yield self.t_dexp_dvar, model, Y, Y_metadata


        self.tearDown()

    #############
    # dpdf_df's #
    #############
    @with_setup(setUp, tearDown)
    def t_logpdf(self, model, Y, f, Y_metadata):
        print("\n{}".format(inspect.stack()[0][3]))
        print(model)
        #print model._get_params()
        np.testing.assert_almost_equal(
                model.pdf(f.copy(), Y.copy(), Y_metadata=Y_metadata).prod(),
                               np.exp(model.logpdf(f.copy(), Y.copy(), Y_metadata=Y_metadata).sum())
                               )

    @with_setup(setUp, tearDown)
    def t_dlogpdf_df(self, model, Y, f, Y_metadata):
        print("\n{}".format(inspect.stack()[0][3]))
        self.description = "\n{}".format(inspect.stack()[0][3])
        logpdf = functools.partial(np.sum(model.logpdf), y=Y, Y_metadata=Y_metadata)
        dlogpdf_df = functools.partial(model.dlogpdf_df, y=Y, Y_metadata=Y_metadata)
        grad = GradientChecker(logpdf, dlogpdf_df, f.copy(), 'g')
        grad.randomize()
        print(model)
        assert grad.checkgrad(verbose=1)

    @with_setup(setUp, tearDown)
    def t_d2logpdf_df2(self, model, Y, f, Y_metadata):
        print("\n{}".format(inspect.stack()[0][3]))
        dlogpdf_df = functools.partial(model.dlogpdf_df, y=Y, Y_metadata=Y_metadata)
        d2logpdf_df2 = functools.partial(model.d2logpdf_df2, y=Y, Y_metadata=Y_metadata)
        grad = GradientChecker(dlogpdf_df, d2logpdf_df2, f.copy(), 'g')
        grad.randomize()
        print(model)
        assert grad.checkgrad(verbose=1)

    @with_setup(setUp, tearDown)
    def t_d3logpdf_df3(self, model, Y, f, Y_metadata):
        print("\n{}".format(inspect.stack()[0][3]))
        d2logpdf_df2 = functools.partial(model.d2logpdf_df2, y=Y, Y_metadata=Y_metadata)
        d3logpdf_df3 = functools.partial(model.d3logpdf_df3, y=Y, Y_metadata=Y_metadata)
        grad = GradientChecker(d2logpdf_df2, d3logpdf_df3, f.copy(), 'g')
        grad.randomize()
        print(model)
        assert grad.checkgrad(verbose=1)

    ##############
    # df_dparams #
    ##############
    @with_setup(setUp, tearDown)
    def t_dlogpdf_dparams(self, model, Y, f, Y_metadata, params, params_names, param_constraints):
        print("\n{}".format(inspect.stack()[0][3]))
        print(model)
        assert (
                dparam_checkgrad(model.logpdf, model.dlogpdf_dtheta,
                    params, params_names, args=(f, Y, Y_metadata), constraints=param_constraints,
                    randomize=False, verbose=True)
                )

    @with_setup(setUp, tearDown)
    def t_dlogpdf_df_dparams(self, model, Y, f, Y_metadata, params, params_names, param_constraints):
        print("\n{}".format(inspect.stack()[0][3]))
        print(model)
        assert (
                dparam_checkgrad(model.dlogpdf_df, model.dlogpdf_df_dtheta,
                    params, params_names, args=(f, Y, Y_metadata), constraints=param_constraints,
                    randomize=False, verbose=True)
                )

    @with_setup(setUp, tearDown)
    def t_d2logpdf2_df2_dparams(self, model, Y, f, Y_metadata, params, params_names, param_constraints):
        print("\n{}".format(inspect.stack()[0][3]))
        print(model)
        assert (
                dparam_checkgrad(model.d2logpdf_df2, model.d2logpdf_df2_dtheta,
                    params, params_names, args=(f, Y, Y_metadata), constraints=param_constraints,
                    randomize=False, verbose=True)
                )

    ################
    # dpdf_dlink's #
    ################
    @with_setup(setUp, tearDown)
    def t_dlogpdf_dlink(self, model, Y, f, Y_metadata, link_f_constraints):
        print("\n{}".format(inspect.stack()[0][3]))
        logpdf = functools.partial(model.logpdf_link, y=Y, Y_metadata=Y_metadata)
        dlogpdf_dlink = functools.partial(model.dlogpdf_dlink, y=Y, Y_metadata=Y_metadata)
        grad = GradientChecker(logpdf, dlogpdf_dlink, f.copy(), 'g')

        #Apply constraints to link_f values
        for constraint in link_f_constraints:
            constraint('g', grad)

        grad.randomize()
        print(grad)
        print(model)
        assert grad.checkgrad(verbose=1)

    @with_setup(setUp, tearDown)
    def t_d2logpdf_dlink2(self, model, Y, f, Y_metadata, link_f_constraints):
        print("\n{}".format(inspect.stack()[0][3]))
        dlogpdf_dlink = functools.partial(model.dlogpdf_dlink, y=Y, Y_metadata=Y_metadata)
        d2logpdf_dlink2 = functools.partial(model.d2logpdf_dlink2, y=Y, Y_metadata=Y_metadata)
        grad = GradientChecker(dlogpdf_dlink, d2logpdf_dlink2, f.copy(), 'g')

        #Apply constraints to link_f values
        for constraint in link_f_constraints:
            constraint('g', grad)

        grad.randomize()
        print(grad)
        print(model)
        assert grad.checkgrad(verbose=1)

    @with_setup(setUp, tearDown)
    def t_d3logpdf_dlink3(self, model, Y, f, Y_metadata, link_f_constraints):
        print("\n{}".format(inspect.stack()[0][3]))
        d2logpdf_dlink2 = functools.partial(model.d2logpdf_dlink2, y=Y, Y_metadata=Y_metadata)
        d3logpdf_dlink3 = functools.partial(model.d3logpdf_dlink3, y=Y, Y_metadata=Y_metadata)
        grad = GradientChecker(d2logpdf_dlink2, d3logpdf_dlink3, f.copy(), 'g')

        #Apply constraints to link_f values
        for constraint in link_f_constraints:
            constraint('g', grad)

        grad.randomize()
        print(grad)
        print(model)
        assert grad.checkgrad(verbose=1)

    #################
    # dlink_dparams #
    #################
    @with_setup(setUp, tearDown)
    def t_dlogpdf_link_dparams(self, model, Y, f, Y_metadata, params, param_names, param_constraints):
        print("\n{}".format(inspect.stack()[0][3]))
        print(model)
        assert (
                dparam_checkgrad(model.logpdf_link, model.dlogpdf_link_dtheta,
                    params, param_names, args=(f, Y, Y_metadata), constraints=param_constraints,
                    randomize=False, verbose=True)
                )

    @with_setup(setUp, tearDown)
    def t_dlogpdf_dlink_dparams(self, model, Y, f, Y_metadata, params, param_names, param_constraints):
        print("\n{}".format(inspect.stack()[0][3]))
        print(model)
        assert (
                dparam_checkgrad(model.dlogpdf_dlink, model.dlogpdf_dlink_dtheta,
                    params, param_names, args=(f, Y, Y_metadata), constraints=param_constraints,
                    randomize=False, verbose=True)
                )

    @with_setup(setUp, tearDown)
    def t_d2logpdf2_dlink2_dparams(self, model, Y, f, Y_metadata, params, param_names, param_constraints):
        print("\n{}".format(inspect.stack()[0][3]))
        print(model)
        assert (
                dparam_checkgrad(model.d2logpdf_dlink2, model.d2logpdf_dlink2_dtheta,
                    params, param_names, args=(f, Y, Y_metadata), constraints=param_constraints,
                    randomize=False, verbose=True)
                )

    ################
    # laplace test #
    ################
    @with_setup(setUp, tearDown)
    def t_laplace_fit_rbf_white(self, model, X, Y, f, Y_metadata, step, param_vals, param_names, constraints):
        print("\n{}".format(inspect.stack()[0][3]))
        #Normalize
        Y = Y/Y.max()
        white_var = 1e-5
        kernel = GPy.kern.RBF(X.shape[1]) + GPy.kern.White(X.shape[1])
        laplace_likelihood = GPy.inference.latent_function_inference.Laplace()

        m = GPy.core.GP(X.copy(), Y.copy(), kernel, likelihood=model, Y_metadata=Y_metadata, inference_method=laplace_likelihood)
        m['.*white'].constrain_fixed(white_var)

        #Set constraints
        for constrain_param, constraint in constraints:
            constraint(constrain_param, m)

        print(m)
        m.randomize()
        m.randomize()

        #Set params
        for param_num in range(len(param_names)):
            name = param_names[param_num]
            m[name] = param_vals[param_num]

        #m.optimize(max_iters=8)
        print(m)
        #if not m.checkgrad(step=step):
            #m.checkgrad(verbose=1, step=step)
            #NOTE this test appears to be stochastic for some likelihoods (student t?)
            # appears to all be working in test mode right now...
        #if isinstance(model, GPy.likelihoods.StudentT):
        assert m.checkgrad(verbose=1, step=step)

    ###########
    # EP test #
    ###########
    @with_setup(setUp, tearDown)
    def t_ep_fit_rbf_white(self, model, X, Y, f, Y_metadata, step, param_vals, param_names, constraints):
        print("\n{}".format(inspect.stack()[0][3]))
        #Normalize
        Y = Y/Y.max()
        white_var = 1e-6
        kernel = GPy.kern.RBF(X.shape[1]) + GPy.kern.White(X.shape[1])
        ep_inf = GPy.inference.latent_function_inference.EP()

        m = GPy.core.GP(X.copy(), Y.copy(), kernel=kernel, likelihood=model, Y_metadata=Y_metadata, inference_method=ep_inf)
        m['.*white'].constrain_fixed(white_var)

        for param_num in range(len(param_names)):
            name = param_names[param_num]
            m[name] = param_vals[param_num]
            constraints[param_num](name, m)

        m.randomize()
        print(m)
        assert m.checkgrad(verbose=1, step=step)

    ################
    # variational expectations #
    ################
    @with_setup(setUp, tearDown)
    def t_varexp(self, model, Y, Y_metadata):
        #Test that the analytic implementation (if it exists) matches the generic gauss
        #hermite implementation
        print("\n{}".format(inspect.stack()[0][3]))
        #Make mu and var (marginal means and variances of q(f)) draws from a GP
        k = GPy.kern.RBF(1).K(np.linspace(0,1,Y.shape[0])[:, None])
        L = GPy.util.linalg.jitchol(k)
        mu = L.dot(np.random.randn(*Y.shape))
        #Variance must be positive
        var = np.abs(L.dot(np.random.randn(*Y.shape))) + 0.01

        expectation = model.variational_expectations(Y=Y, m=mu, v=var, gh_points=None, Y_metadata=Y_metadata)[0]

        #Implementation of gauss hermite integration
        shape = mu.shape
        gh_x, gh_w= np.polynomial.hermite.hermgauss(50)
        m,v,Y = mu.flatten(), var.flatten(), Y.flatten()
        #make a grid of points
        X = gh_x[None,:]*np.sqrt(2.*v[:,None]) + m[:,None]
        #evaluate the likelhood for the grid. First ax indexes the data (and mu, var) and the second indexes the grid.
        # broadcast needs to be handled carefully.
        logp = model.logpdf(X, Y[:,None], Y_metadata=Y_metadata)
        #average over the gird to get derivatives of the Gaussian's parameters
        #division by pi comes from fact that for each quadrature we need to scale by 1/sqrt(pi)
        expectation_gh  = np.dot(logp, gh_w)/np.sqrt(np.pi)
        expectation_gh = expectation_gh.reshape(*shape)

        np.testing.assert_almost_equal(expectation, expectation_gh, decimal=5)

    @with_setup(setUp, tearDown)
    def t_dexp_dmu(self, model, Y, Y_metadata):
        print("\n{}".format(inspect.stack()[0][3]))
        #Make mu and var (marginal means and variances of q(f)) draws from a GP
        k = GPy.kern.RBF(1).K(np.linspace(0,1,Y.shape[0])[:, None])
        L = GPy.util.linalg.jitchol(k)
        mu = L.dot(np.random.randn(*Y.shape))
        #Variance must be positive
        var = np.abs(L.dot(np.random.randn(*Y.shape))) + 0.01
        expectation = functools.partial(model.variational_expectations, Y=Y, v=var, gh_points=None, Y_metadata=Y_metadata)

        #Function to get the nth returned value
        def F(mu):
            return expectation(m=mu)[0]
        def dmu(mu):
            return expectation(m=mu)[1]

        grad = GradientChecker(F, dmu, mu.copy(), 'm')

        grad.randomize()
        print(grad)
        print(model)
        assert grad.checkgrad(verbose=1)

    @with_setup(setUp, tearDown)
    def t_dexp_dvar(self, model, Y, Y_metadata):
        print("\n{}".format(inspect.stack()[0][3]))
        #Make mu and var (marginal means and variances of q(f)) draws from a GP
        k = GPy.kern.RBF(1).K(np.linspace(0,1,Y.shape[0])[:, None])
        L = GPy.util.linalg.jitchol(k)
        mu = L.dot(np.random.randn(*Y.shape))
        #Variance must be positive
        var = np.abs(L.dot(np.random.randn(*Y.shape))) + 0.01
        expectation = functools.partial(model.variational_expectations, Y=Y, m=mu, gh_points=None, Y_metadata=Y_metadata)

        #Function to get the nth returned value
        def F(var):
            return expectation(v=var)[0]
        def dvar(var):
            return expectation(v=var)[2]

        grad = GradientChecker(F, dvar, var.copy(), 'v')

        self.constrain_positive('v', grad)
        #grad.randomize()
        print(grad)
        print(model)
        assert grad.checkgrad(verbose=1)

class LaplaceTests(unittest.TestCase):
    """
    Specific likelihood tests, not general enough for the above tests
    """

    def setUp(self):
        np.random.seed(fixed_seed)
        self.N = 15
        self.D = 1
        self.X = np.random.rand(self.N, self.D)*10

        self.real_std = 0.1
        noise = np.random.randn(*self.X[:, 0].shape)*self.real_std
        self.Y = (np.sin(self.X[:, 0]*2*np.pi) + noise)[:, None]
        self.f = np.random.rand(self.N, 1)

        self.var = 0.2

        self.var = np.random.rand(1)
        self.stu_t = GPy.likelihoods.StudentT(deg_free=5, sigma2=self.var)
        #TODO: gaussians with on Identity link. self.gauss = GPy.likelihoods.Gaussian(gp_link=link_functions.Log(), variance=self.var)
        self.gauss = GPy.likelihoods.Gaussian(variance=self.var)

        #Make a bigger step as lower bound can be quite curved
        self.step = 1e-6

    def tearDown(self):
        self.stu_t = None
        self.gauss = None
        self.Y = None
        self.f = None
        self.X = None

    def test_gaussian_d2logpdf_df2_2(self):
        print("\n{}".format(inspect.stack()[0][3]))
        self.Y = None

        self.N = 2
        self.D = 1
        self.X = np.linspace(0, self.D, self.N)[:, None]
        self.real_std = 0.2
        noise = np.random.randn(*self.X.shape)*self.real_std
        self.Y = np.sin(self.X*2*np.pi) + noise
        self.f = np.random.rand(self.N, 1)

        dlogpdf_df = functools.partial(self.gauss.dlogpdf_df, y=self.Y)
        d2logpdf_df2 = functools.partial(self.gauss.d2logpdf_df2, y=self.Y)
        grad = GradientChecker(dlogpdf_df, d2logpdf_df2, self.f.copy(), 'g')
        grad.randomize()

        self.assertTrue(grad.checkgrad(verbose=1))

    def test_laplace_log_likelihood(self):
        debug = False
        real_std = 0.1
        initial_var_guess = 0.5

        #Start a function, any function
        X = np.linspace(0.0, np.pi*2, 100)[:, None]
        Y = np.sin(X) + np.random.randn(*X.shape)*real_std
        Y = Y/Y.max()
        #Yc = Y.copy()
        #Yc[75:80] += 1
        kernel1 = GPy.kern.RBF(X.shape[1]) + GPy.kern.White(X.shape[1])
        #FIXME: Make sure you can copy kernels when params is fixed
        #kernel2 = kernel1.copy()
        kernel2 = GPy.kern.RBF(X.shape[1]) + GPy.kern.White(X.shape[1])

        gauss_distr1 = GPy.likelihoods.Gaussian(variance=initial_var_guess)
        exact_inf = GPy.inference.latent_function_inference.ExactGaussianInference()
        m1 = GPy.core.GP(X, Y.copy(), kernel=kernel1, likelihood=gauss_distr1, inference_method=exact_inf)
        m1['.*white'].constrain_fixed(1e-6)
        m1['.*Gaussian_noise.variance'].constrain_bounded(1e-4, 10)
        m1.randomize()

        gauss_distr2 = GPy.likelihoods.Gaussian(variance=initial_var_guess)
        laplace_inf = GPy.inference.latent_function_inference.Laplace()
        m2 = GPy.core.GP(X, Y.copy(), kernel=kernel2, likelihood=gauss_distr2, inference_method=laplace_inf)
        m2['.*white'].constrain_fixed(1e-6)
        m2['.*Gaussian_noise.variance'].constrain_bounded(1e-4, 10)
        m2.randomize()

        if debug:
            print(m1)
            print(m2)

        optimizer = 'scg'
        print("Gaussian")
        m1.optimize(optimizer, messages=debug, ipython_notebook=False)
        print("Laplace Gaussian")
        m2.optimize(optimizer, messages=debug, ipython_notebook=False)
        if debug:
            print(m1)
            print(m2)

        m2[:] = m1[:]

        #Predict for training points to get posterior mean and variance
        post_mean, post_var = m1.predict(X)
        post_mean_approx, post_var_approx, = m2.predict(X)

        if debug:
            from matplotlib import pyplot as pb
            pb.figure(5)
            pb.title('posterior means')
            pb.scatter(X, post_mean, c='g')
            pb.scatter(X, post_mean_approx, c='r', marker='x')

            pb.figure(6)
            pb.title('plot_f')
            m1.plot_f(fignum=6)
            m2.plot_f(fignum=6)
            fig, axes = pb.subplots(2, 1)
            fig.suptitle('Covariance matricies')
            a1 = pb.subplot(121)
            a1.matshow(m1.likelihood.covariance_matrix)
            a2 = pb.subplot(122)
            a2.matshow(m2.likelihood.covariance_matrix)

            pb.figure(8)
            pb.scatter(X, m1.likelihood.Y, c='g')
            pb.scatter(X, m2.likelihood.Y, c='r', marker='x')

        #Check Y's are the same
        np.testing.assert_almost_equal(m1.Y, m2.Y, decimal=5)
        #Check marginals are the same
        np.testing.assert_almost_equal(m1.log_likelihood(), m2.log_likelihood(), decimal=2)
        #Check marginals are the same with random
        m1.randomize()
        m2[:] = m1[:]

        np.testing.assert_almost_equal(m1.log_likelihood(), m2.log_likelihood(), decimal=2)

        #Check they are checkgradding
        #m1.checkgrad(verbose=1)
        #m2.checkgrad(verbose=1)
        self.assertTrue(m1.checkgrad(verbose=True))
        self.assertTrue(m2.checkgrad(verbose=True))

if __name__ == "__main__":
    print("Running unit tests")
    unittest.main()
