Exemple #1
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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import numpy as np
import scipy as sp
import scipy.io
import matplotlib.pyplot as plt

import d3s.domain as domain
import d3s.kernels as kernels
import d3s.algorithms as algorithms
import d3s.systems as systems

plt.ion()

#%% Ornstein-Uhlenbeck process
Omega = domain.discretization(np.array([[-2, 2]]), np.array([50]))

f = systems.OrnsteinUhlenbeck(0.001, 500)
X = Omega.randPerBox(100)
Y = f(X)

sigma = np.sqrt(0.3)
epsilon = 0.1
k = kernels.gaussianKernel(sigma)

evs = 4  # number of eigenfunctions to be computed

# Perron-Frobenius
d, V = algorithms.kedmd(X, Y, k, epsilon=epsilon, evs=evs, operator='P')
for i in range(evs):
    plt.figure()
Exemple #2
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    a = s @ s.T
    tra = np.trace(a)
    for i in range(m):
        for j in range(m):
            G_10[i, j] = -1/k.sigma**2 * (B[i, i] - B[i, j]) \
                        + 0.5*(1/k.sigma**4 * np.dot(X[:, i]-X[:, j], a @ (X[:, i]-X[:, j])) - 1/k.sigma**2 * tra )
    G_10 = G_10 * G_00
    return (G_00, G_10)


#%% Ornstein-Uhlenbeck process --------------------------------------------------------------------

#%% define domain
bounds = np.array([[-2, 2]])
boxes = np.array([100])
Omega = domain.discretization(bounds, boxes)

#%% define system
alpha = 1
beta = 4


def b(x):
    return -alpha * x


def sigma(x):
    return np.sqrt(2 / beta) * np.ones((1, 1, x.shape[1]))


#%% generate data
Exemple #3
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import d3s.kernels as kernels
import d3s.domain as domain
import d3s.ceig as ceig
import d3s.antisymmetricKernels as akernels

#%% two electrons in a box

# define parameters
h  = 1
m0 = 1
L  = np.pi

# define domain
bounds = np.array([[0, L], [0, L]])
boxes = np.array([31, 31])
Omega = domain.discretization(bounds, boxes)

# generate data
X, isBoundary = Omega.vertexGrid()
m = Omega.numVertices()

# replace regular grid
nr = np.count_nonzero(isBoundary)

n_new = 1000
X = np.hstack( (X[:, isBoundary], Omega.rand(n_new)) )
isBoundary = np.hstack( (np.ones(nr, dtype='bool'), np.zeros(n_new, dtype='bool') ))

m = X.shape[1]

#%% plot boundary