Python tensor.sqrt方法代码示例

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def adagrad(self, cost, params, lr=1.0, epsilon=1e-6,consider_constant=None):
        """
        Adagrad. Based on http://www.ark.cs.cmu.edu/cdyer/adagrad.pdf
        """
        lr = theano.shared(np.float32(lr).astype(floatX))
        epsilon = theano.shared(np.float32(epsilon).astype(floatX))

        gradients = self.get_gradients(cost, params,consider_constant)
        gsums = [theano.shared(np.zeros_like(param.get_value(borrow=True)).astype(floatX)) for param in params]

        updates = []
        for param, gradient, gsum in zip(params, gradients, gsums):
            new_gsum = gsum + gradient ** 2.
            updates.append((gsum, new_gsum))
            updates.append((param, param - lr * gradient / (T.sqrt(gsum + epsilon))))
        return updates 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def adadelta(self, cost, params, rho=0.95, epsilon=1e-6,consider_constant=None):
        """
        Adadelta. Based on:
        http://www.matthewzeiler.com/pubs/googleTR2012/googleTR2012.pdf
        """
        rho = theano.shared(np.float32(rho).astype(floatX))
        epsilon = theano.shared(np.float32(epsilon).astype(floatX))

        gradients = self.get_gradients(cost, params,consider_constant)
        accu_gradients = [theano.shared(np.zeros_like(param.get_value(borrow=True)).astype(floatX)) for param in params]
        accu_deltas = [theano.shared(np.zeros_like(param.get_value(borrow=True)).astype(floatX)) for param in params]

        updates = []
        for param, gradient, accu_gradient, accu_delta in zip(params, gradients, accu_gradients, accu_deltas):
            new_accu_gradient = rho * accu_gradient + (1. - rho) * gradient ** 2.
            delta_x = - T.sqrt((accu_delta + epsilon) / (new_accu_gradient + epsilon)) * gradient
            new_accu_delta = rho * accu_delta + (1. - rho) * delta_x ** 2.
            updates.append((accu_gradient, new_accu_gradient))
            updates.append((accu_delta, new_accu_delta))
            updates.append((param, param + delta_x))
        return updates 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def rmsprop(self, cost, params, lr=0.001, rho=0.9, eps=1e-6,consider_constant=None):
        """
        RMSProp.
        """
        lr = theano.shared(np.float32(lr).astype(floatX))

        gradients = self.get_gradients(cost, params,consider_constant)
        accumulators = [theano.shared(np.zeros_like(p.get_value()).astype(np.float32)) for p in params]

        updates = []

        for param, gradient, accumulator in zip(params, gradients, accumulators):
            new_accumulator = rho * accumulator + (1 - rho) * gradient ** 2
            updates.append((accumulator, new_accumulator))

            new_param = param - lr * gradient / T.sqrt(new_accumulator + eps)
            updates.append((param, new_param))

        return updates 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def Adam(cost, params, lr=0.0002, b1=0.1, b2=0.001, e=1e-8):
    updates = []
    grads = T.grad(cost, params)
    i = theano.shared(np.array(0., theano.config.floatX))
    i_t = i + 1.
    fix1 = 1. - (1. - b1)**i_t
    fix2 = 1. - (1. - b2)**i_t
    lr_t = lr * (T.sqrt(fix2) / fix1)
    for p, g in zip(params, grads):
        m = theano.shared(p.get_value() * 0.)
        v = theano.shared(p.get_value() * 0.)
        m_t = (b1 * g) + ((1. - b1) * m)
        v_t = (b2 * T.sqr(g)) + ((1. - b2) * v)
        g_t = m_t / (T.sqrt(v_t) + e)
        p_t = p - (lr_t * g_t)
        updates.append((m, m_t))
        updates.append((v, v_t))
        updates.append((p, p_t))
    updates.append((i, i_t))
    return updates 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def RMSprop(cost, params, lr=0.001, rho=0.9, epsilon=1e-6, grads=None):
    # From:
    # https://github.com/Newmu/Theano-Tutorials/blob/master/4_modern_net.py
    if grads is None:
        grads = T.grad(cost=cost, wrt=params)
    assert len(grads) == len(params)

    updates = []
    for p, g in zip(params, grads):
        acc = theano.shared(np.zeros_like(p.get_value(), dtype=np.float32),
                            name="%s/rms/acc" % p.name)
        acc_new = rho * acc + (1 - rho) * g ** 2
        gradient_scaling = T.sqrt(acc_new + epsilon)
        g = g / gradient_scaling
        updates.append((acc, acc_new))
        updates.append((p, p - lr * g))
    return updates 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def adam(self, param, grad, updates, sample_idx=None, epsilon=1e-6):
        v1 = np.float32(self.decay)
        v2 = np.float32(1.0 - self.decay)
        acc = theano.shared(param.get_value(borrow=False) * 0., borrow=True)
        meang = theano.shared(param.get_value(borrow=False) * 0., borrow=True)
        countt = theano.shared(param.get_value(borrow=False) * 0., borrow=True)
        if sample_idx is None:
            acc_new = v1 * acc + v2 * grad ** 2
            meang_new = v1 * meang + v2 * grad
            countt_new = countt + 1
            updates[acc] = acc_new
            updates[meang] = meang_new
            updates[countt] = countt_new
        else:
            acc_s = acc[sample_idx]
            meang_s = meang[sample_idx]
            countt_s = countt[sample_idx]
            acc_new = v1 * acc_s + v2 * grad ** 2
            meang_new = v1 * meang_s + v2 * grad
            countt_new = countt_s + 1.0
            updates[acc] = T.set_subtensor(acc_s, acc_new)
            updates[meang] = T.set_subtensor(meang_s, meang_new)
            updates[countt] = T.set_subtensor(countt_s, countt_new)
        return (meang_new / (1 - v1 ** countt_new)) / (T.sqrt(acc_new / (1 - v1 ** countt_new)) + epsilon) 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def get_noise(self, size):

        # Allow just requesting batch size
        if isinstance(size, int):
            size = (size, self.get_input_space().get_total_dimension())

        if not hasattr(self, 'noise'):
            self.noise = "gaussian"
        if self.noise == "uniform":
            return self.theano_rng.uniform(low=-np.sqrt(3), high=np.sqrt(3), size=size, dtype='float32')
        elif self.noise == "gaussian":
            return self.theano_rng.normal(size=size, dtype='float32')
        elif self.noise == "spherical":
            noise = self.theano_rng.normal(size=size, dtype='float32')
            noise = noise / T.maximum(1e-7, T.sqrt(T.sqr(noise).sum(axis=1))).dimshuffle(0, 'x')
            return noise
        else:
            raise NotImplementedError(self.noise) 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def _modify_updates(self, updates):
        """
        Replaces the values in `updates` if needed to enforce the options set
        in the __init__ method, including `max_kernel_norm`.

        Parameters
        ----------
        updates : OrderedDict
            A dictionary mapping parameters (including parameters not
            belonging to this model) to updated values of those parameters.
            The dictionary passed in contains the updates proposed by the
            learning algorithm. This function modifies the dictionary
            directly. The modified version will be compiled and executed
            by the learning algorithm.
        """

        if self.max_kernel_norm is not None:
            W, = self.transformer.get_params()
            if W in updates:
                updated_W = updates[W]
                row_norms = T.sqrt(T.sum(T.sqr(updated_W), axis=(0, 1, 2)))
                desired_norms = T.clip(row_norms, 0, self.max_kernel_norm)
                scales = desired_norms / (1e-7 + row_norms)
                updates[W] = (updated_W * scales.dimshuffle('x', 'x', 'x', 0)) 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def adam_updates(params, cost, lr=0.001, mom1=0.9, mom2=0.999):
    updates = []
    grads = T.grad(cost, params)
    t = th.shared(np.cast[th.config.floatX](1.))
    for p, g in zip(params, grads):
        v = th.shared(np.cast[th.config.floatX](p.get_value() * 0.))
        mg = th.shared(np.cast[th.config.floatX](p.get_value() * 0.))
        v_t = mom1*v + (1. - mom1)*g
        mg_t = mom2*mg + (1. - mom2)*T.square(g)
        v_hat = v_t / (1. - mom1 ** t)
        mg_hat = mg_t / (1. - mom2 ** t)
        g_t = v_hat / T.sqrt(mg_hat + 1e-8)
        p_t = p - lr * g_t
        updates.append((v, v_t))
        updates.append((mg, mg_t))
        updates.append((p, p_t))
    updates.append((t, t+1))
    return updates 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def get_output_for(self, input, deterministic=False, **kwargs):
        if deterministic:
            norm_features = (input-self.avg_batch_mean.dimshuffle(*self.dimshuffle_args)) / T.sqrt(1e-6 + self.avg_batch_var).dimshuffle(*self.dimshuffle_args)
        else:
            batch_mean = T.mean(input,axis=self.axes_to_sum).flatten()
            centered_input = input-batch_mean.dimshuffle(*self.dimshuffle_args)
            batch_var = T.mean(T.square(centered_input),axis=self.axes_to_sum).flatten()
            batch_stdv = T.sqrt(1e-6 + batch_var)
            norm_features = centered_input / batch_stdv.dimshuffle(*self.dimshuffle_args)

            # BN updates
            new_m = 0.9*self.avg_batch_mean + 0.1*batch_mean
            new_v = 0.9*self.avg_batch_var + T.cast((0.1*input.shape[0])/(input.shape[0]-1),th.config.floatX)*batch_var
            self.bn_updates = [(self.avg_batch_mean, new_m), (self.avg_batch_var, new_v)]

        if hasattr(self, 'g'):
            activation = norm_features*self.g.dimshuffle(*self.dimshuffle_args)
        else:
            activation = norm_features
        if hasattr(self, 'b'):
            activation += self.b.dimshuffle(*self.dimshuffle_args)

        return self.nonlinearity(activation) 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def rbf_mmd2_streaming_and_ratio(X, Y, sigma=0):
    # n = (T.smallest(X.shape[0], Y.shape[0]) // 2) * 2
    n = (X.shape[0] // 2) * 2
    gamma = 1 / (2 * sigma**2)
    rbf = lambda A, B: T.exp(-gamma * ((A - B) ** 2).sum(axis=1))
    h_bits = (rbf(X[:n:2], X[1:n:2]) + rbf(Y[:n:2], Y[1:n:2])
            - rbf(X[:n:2], Y[1:n:2]) - rbf(X[1:n:2], Y[:n:2]))

    mmd2 = h_bits.mean()

    # variance is 1/2 E_{v, v'} (h(v) - h(v'))^2
    # estimate with even, odd diffs
    m = (n // 2) * 2
    approx_var = 1/2 * ((h_bits[:m:2] - h_bits[1:m:2]) ** 2).mean()
    ratio = mmd2 / T.sqrt(T.largest(approx_var, _eps))
    return mmd2, ratio


################################################################################
### MMD with linear kernel

# Hotelling test statistic is from:
#    Jitkrittum, Szabo, Chwialkowski, and Gretton.
#    Interpretable Distribution Features with Maximum Testing Power.
#    NIPS 2015. 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def __call__(self, params, cost):
        updates = []
        grads = T.grad(cost, params)
        grads = clip_norms(grads, self.clipnorm)
        t = theano.shared(floatX(1.))
        b1_t = self.b1 * self.l**(t - 1)

        for p, g in zip(params, grads):
            g = self.regularizer.gradient_regularize(p, g)
            m = theano.shared(p.get_value() * 0.)
            v = theano.shared(p.get_value() * 0.)

            m_t = b1_t * m + (1 - b1_t) * g
            v_t = self.b2 * v + (1 - self.b2) * g**2
            m_c = m_t / (1 - self.b1**t)
            v_c = v_t / (1 - self.b2**t)
            p_t = p - (self.lr * m_c) / (T.sqrt(v_c) + self.e)
            p_t = self.regularizer.weight_regularize(p_t)
            updates.append((m, m_t))
            updates.append((v, v_t))
            updates.append((p, p_t))
        updates.append((t, t + 1.))
        return updates 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def __init__(self):
        def f(x, u, i, terminal):
            if terminal:
                ctrl_cost = T.zeros_like(x[..., 0])
            else:
                ctrl_cost = T.square(u).sum(axis=-1)

            # x: (batch_size, 8)
            # x[..., 0:4]: qpos
            # x[..., 4:8]: qvel, time derivatives of qpos, not used in the cost.
            theta = x[..., 0]  # qpos[0]: angle of joint 0
            phi = x[..., 1]  # qpos[1]: angle of joint 1
            target_xpos = x[..., 2:4]  # qpos[2:4], target x & y coordinate
            body1_xpos = 0.1 * T.stack([T.cos(theta), T.sin(theta)], axis=1)
            tip_xpos_incr = 0.11 * T.stack([T.cos(phi), T.sin(phi)], axis=1)
            tip_xpos = body1_xpos + tip_xpos_incr
            delta = tip_xpos - target_xpos

            state_cost = T.sqrt(T.sum(delta * delta, axis=-1))
            cost = state_cost + ctrl_cost

            return cost

        super().__init__(f, state_size=8, action_size=2) 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def adadelta(lr, tparams, grads, inp, cost):
    running_up2 = [theano.shared(p.get_value() * numpy.float32(0.), name='%s_rup2'%k) for k, p in tparams.iteritems()]
    running_grads2 = [theano.shared(p.get_value() * numpy.float32(0.), name='%s_rgrad2'%k) for k, p in tparams.iteritems()]

    rg2_new = [0.95 * rg2 + 0.05 * (g ** 2) for rg2, g in zip(running_grads2, grads)]
    rg2up = [(rg2, r_n) for rg2, r_n in zip(running_grads2, rg2_new)]
    
    
    updir = [-tensor.sqrt(ru2 + 1e-6) / tensor.sqrt(rg2 + 1e-6) * zg for zg, ru2, rg2 in zip(grads, running_up2, rg2_new)]
    ru2up = [(ru2, 0.95 * ru2 + 0.05 * (ud ** 2)) for ru2, ud in zip(running_up2, updir)]
    param_up = [(p, p + ud) for p, ud in zip(itemlist(tparams), updir)]

    inp += [lr]
    f_update = theano.function(inp, cost, updates=rg2up+ru2up+param_up, on_unused_input='ignore', profile=profile)

    return f_update 

# 需要导入模块: from theano import tensor [as 别名]
# 或者: from theano.tensor import sqrt [as 别名]
def debugging_adadelta(lr, tparams, grads, inp, cost):
    zipped_grads = [theano.shared(p.get_value() * numpy.float32(0.), name='%s_grad'%k) for k, p in tparams.iteritems()]
    running_up2 = [theano.shared(p.get_value() * numpy.float32(0.), name='%s_rup2'%k) for k, p in tparams.iteritems()]
    running_grads2 = [theano.shared(p.get_value() * numpy.float32(0.), name='%s_rgrad2'%k) for k, p in tparams.iteritems()]

    zgup = [(zg, g) for zg, g in zip(zipped_grads, grads)]
    rg2up = [(rg2, 0.95 * rg2 + 0.05 * (g ** 2)) for rg2, g in zip(running_grads2, grads)]

    f_grad_shared = theano.function(inp, cost, updates=zgup+rg2up, profile=profile)
    
    
    updir = [-tensor.sqrt(ru2 + 1e-6) / tensor.sqrt(rg2 + 1e-6) * zg for zg, ru2, rg2 in zip(zipped_grads, running_up2, running_grads2)]
    ru2up = [(ru2, 0.95 * ru2 + 0.05 * (ud ** 2)) for ru2, ud in zip(running_up2, updir)]
    param_up = [(p, p + ud) for p, ud in zip(itemlist(tparams), updir)]

    f_update = theano.function([lr], [], updates=ru2up+param_up, on_unused_input='ignore', profile=profile)

    return f_grad_shared, f_update