diff options
Diffstat (limited to 'examples/backends')
| -rw-r--r-- | examples/backends/plot_sliced_wass_grad_flow_pytorch.py | 10 | ||||
| -rw-r--r-- | examples/backends/plot_ssw_unif_torch.py | 153 |
2 files changed, 158 insertions, 5 deletions
diff --git a/examples/backends/plot_sliced_wass_grad_flow_pytorch.py b/examples/backends/plot_sliced_wass_grad_flow_pytorch.py index cf5d64d..f00de50 100644 --- a/examples/backends/plot_sliced_wass_grad_flow_pytorch.py +++ b/examples/backends/plot_sliced_wass_grad_flow_pytorch.py @@ -74,7 +74,7 @@ x_all = np.zeros((nb_iter_max, x1.shape[0], 2)) loss_iter = [] # generator for random permutations -gen = torch.Generator() +gen = torch.Generator(device=device) gen.manual_seed(42) for i in range(nb_iter_max): @@ -103,7 +103,7 @@ ax = pl.axis() # %% # Animate trajectories of the gradient flow along iteration -# ------------------------------------------------------- +# --------------------------------------------------------- pl.figure(3, (8, 4)) @@ -122,7 +122,7 @@ ani = animation.FuncAnimation(pl.gcf(), _update_plot, nb_iter_max, interval=100, # %% # Compute the Sliced Wasserstein Barycenter -# +# ----------------------------------------- x1_torch = torch.tensor(x1).to(device=device) x3_torch = torch.tensor(x3).to(device=device) xbinit = np.random.randn(500, 2) * 10 + 16 @@ -136,7 +136,7 @@ x_all = np.zeros((nb_iter_max, xbary_torch.shape[0], 2)) loss_iter = [] # generator for random permutations -gen = torch.Generator() +gen = torch.Generator(device=device) gen.manual_seed(42) alpha = 0.5 @@ -169,7 +169,7 @@ ax = pl.axis() # %% # Animate trajectories of the barycenter along gradient descent -# ------------------------------------------------------- +# ------------------------------------------------------------- pl.figure(5, (8, 4)) diff --git a/examples/backends/plot_ssw_unif_torch.py b/examples/backends/plot_ssw_unif_torch.py new file mode 100644 index 0000000..7ccc2af --- /dev/null +++ b/examples/backends/plot_ssw_unif_torch.py @@ -0,0 +1,153 @@ +# -*- coding: utf-8 -*- +r""" +================================================ +Spherical Sliced-Wasserstein Embedding on Sphere +================================================ + +Here, we aim at transforming samples into a uniform +distribution on the sphere by minimizing SSW: + +.. math:: + \min_{x} SSW_2(\nu, \frac{1}{n}\sum_{i=1}^n \delta_{x_i}) + +where :math:`\nu=\mathrm{Unif}(S^1)`. + +""" + +# Author: Clément Bonet <clement.bonet@univ-ubs.fr> +# +# License: MIT License + +# sphinx_gallery_thumbnail_number = 3 + +import numpy as np +import matplotlib.pyplot as pl +import matplotlib.animation as animation +import torch +import torch.nn.functional as F + +import ot + + +# %% +# Data generation +# --------------- + +torch.manual_seed(1) + +N = 1000 +x0 = torch.rand(N, 3) +x0 = F.normalize(x0, dim=-1) + + +# %% +# Plot data +# --------- + +def plot_sphere(ax): + xlist = np.linspace(-1.0, 1.0, 50) + ylist = np.linspace(-1.0, 1.0, 50) + r = np.linspace(1.0, 1.0, 50) + X, Y = np.meshgrid(xlist, ylist) + + Z = np.sqrt(np.maximum(r**2 - X**2 - Y**2, 0)) + + ax.plot_wireframe(X, Y, Z, color="gray", alpha=.3) + ax.plot_wireframe(X, Y, -Z, color="gray", alpha=.3) # Now plot the bottom half + + +# plot the distributions +pl.figure(1) +ax = pl.axes(projection='3d') +plot_sphere(ax) +ax.scatter(x0[:, 0], x0[:, 1], x0[:, 2], label='Data samples', alpha=0.5) +ax.set_title('Data distribution') +ax.legend() + + +# %% +# Gradient descent +# ---------------- + +x = x0.clone() +x.requires_grad_(True) + +n_iter = 500 +lr = 100 + +losses = [] +xvisu = torch.zeros(n_iter, N, 3) + +for i in range(n_iter): + sw = ot.sliced_wasserstein_sphere_unif(x, n_projections=500) + grad_x = torch.autograd.grad(sw, x)[0] + + x = x - lr * grad_x + x = F.normalize(x, p=2, dim=1) + + losses.append(sw.item()) + xvisu[i, :, :] = x.detach().clone() + + if i % 100 == 0: + print("Iter: {:3d}, loss={}".format(i, losses[-1])) + +pl.figure(1) +pl.semilogy(losses) +pl.grid() +pl.title('SSW') +pl.xlabel("Iterations") + + +# %% +# Plot trajectories of generated samples along iterations +# ------------------------------------------------------- + +ivisu = [0, 25, 50, 75, 100, 150, 200, 350, 499] + +fig = pl.figure(3, (10, 10)) +for i in range(9): + # pl.subplot(3, 3, i + 1) + # ax = pl.axes(projection='3d') + ax = fig.add_subplot(3, 3, i + 1, projection='3d') + plot_sphere(ax) + ax.scatter(xvisu[ivisu[i], :, 0], xvisu[ivisu[i], :, 1], xvisu[ivisu[i], :, 2], label='Data samples', alpha=0.5) + ax.set_title('Iter. {}'.format(ivisu[i])) + #ax.axis("off") + if i == 0: + ax.legend() + + +# %% +# Animate trajectories of generated samples along iteration +# ------------------------------------------------------- + +pl.figure(4, (8, 8)) + + +def _update_plot(i): + i = 3 * i + pl.clf() + ax = pl.axes(projection='3d') + plot_sphere(ax) + ax.scatter(xvisu[i, :, 0], xvisu[i, :, 1], xvisu[i, :, 2], label='Data samples$', alpha=0.5) + ax.axis("off") + ax.set_xlim((-1.5, 1.5)) + ax.set_ylim((-1.5, 1.5)) + ax.set_title('Iter. {}'.format(i)) + return 1 + + +print(xvisu.shape) + +i = 0 +ax = pl.axes(projection='3d') +plot_sphere(ax) +ax.scatter(xvisu[i, :, 0], xvisu[i, :, 1], xvisu[i, :, 2], label='Data samples from $G\#\mu_n$', alpha=0.5) +ax.axis("off") +ax.set_xlim((-1.5, 1.5)) +ax.set_ylim((-1.5, 1.5)) +ax.set_title('Iter. {}'.format(ivisu[i])) + + +ani = animation.FuncAnimation(pl.gcf(), _update_plot, n_iter // 5, interval=100, repeat_delay=2000) +# %% |