1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189
|
"""
===================
Stochastic examples
===================
This example is designed to show how to use the stochatic optimization
algorithms for discrete and semi-continuous measures from the POT library.
[18] Genevay, A., Cuturi, M., Peyré, G. & Bach, F.
Stochastic Optimization for Large-scale Optimal Transport.
Advances in Neural Information Processing Systems (2016).
[19] Seguy, V., Bhushan Damodaran, B., Flamary, R., Courty, N., Rolet, A. &
Blondel, M. Large-scale Optimal Transport and Mapping Estimation.
International Conference on Learning Representation (2018)
"""
# Author: Kilian Fatras <kilian.fatras@gmail.com>
#
# License: MIT License
import matplotlib.pylab as pl
import numpy as np
import ot
import ot.plot
#############################################################################
# Compute the Transportation Matrix for the Semi-Dual Problem
# -----------------------------------------------------------
#
# Discrete case
# `````````````
#
# Sample two discrete measures for the discrete case and compute their cost
# matrix c.
n_source = 7
n_target = 4
reg = 1
numItermax = 1000
a = ot.utils.unif(n_source)
b = ot.utils.unif(n_target)
rng = np.random.RandomState(0)
X_source = rng.randn(n_source, 2)
Y_target = rng.randn(n_target, 2)
M = ot.dist(X_source, Y_target)
#############################################################################
# Call the "SAG" method to find the transportation matrix in the discrete case
method = "SAG"
sag_pi = ot.stochastic.solve_semi_dual_entropic(a, b, M, reg, method,
numItermax)
print(sag_pi)
#############################################################################
# Semi-Continuous Case
# ````````````````````
#
# Sample one general measure a, one discrete measures b for the semicontinous
# case, the points where source and target measures are defined and compute the
# cost matrix.
n_source = 7
n_target = 4
reg = 1
numItermax = 1000
log = True
a = ot.utils.unif(n_source)
b = ot.utils.unif(n_target)
rng = np.random.RandomState(0)
X_source = rng.randn(n_source, 2)
Y_target = rng.randn(n_target, 2)
M = ot.dist(X_source, Y_target)
#############################################################################
# Call the "ASGD" method to find the transportation matrix in the semicontinous
# case.
method = "ASGD"
asgd_pi, log_asgd = ot.stochastic.solve_semi_dual_entropic(a, b, M, reg, method,
numItermax, log=log)
print(log_asgd['alpha'], log_asgd['beta'])
print(asgd_pi)
#############################################################################
# Compare the results with the Sinkhorn algorithm
sinkhorn_pi = ot.sinkhorn(a, b, M, reg)
print(sinkhorn_pi)
##############################################################################
# Plot Transportation Matrices
# ````````````````````````````
#
# For SAG
pl.figure(4, figsize=(5, 5))
ot.plot.plot1D_mat(a, b, sag_pi, 'semi-dual : OT matrix SAG')
pl.show()
##############################################################################
# For ASGD
pl.figure(4, figsize=(5, 5))
ot.plot.plot1D_mat(a, b, asgd_pi, 'semi-dual : OT matrix ASGD')
pl.show()
##############################################################################
# For Sinkhorn
pl.figure(4, figsize=(5, 5))
ot.plot.plot1D_mat(a, b, sinkhorn_pi, 'OT matrix Sinkhorn')
pl.show()
#############################################################################
# Compute the Transportation Matrix for the Dual Problem
# ------------------------------------------------------
#
# Semi-continuous case
# ````````````````````
#
# Sample one general measure a, one discrete measures b for the semi-continuous
# case and compute the cost matrix c.
n_source = 7
n_target = 4
reg = 1
numItermax = 100000
lr = 0.1
batch_size = 3
log = True
a = ot.utils.unif(n_source)
b = ot.utils.unif(n_target)
rng = np.random.RandomState(0)
X_source = rng.randn(n_source, 2)
Y_target = rng.randn(n_target, 2)
M = ot.dist(X_source, Y_target)
#############################################################################
#
# Call the "SGD" dual method to find the transportation matrix in the
# semi-continuous case
sgd_dual_pi, log_sgd = ot.stochastic.solve_dual_entropic(a, b, M, reg,
batch_size, numItermax,
lr, log=log)
print(log_sgd['alpha'], log_sgd['beta'])
print(sgd_dual_pi)
#############################################################################
#
# Compare the results with the Sinkhorn algorithm
# ```````````````````````````````````````````````
#
# Call the Sinkhorn algorithm from POT
sinkhorn_pi = ot.sinkhorn(a, b, M, reg)
print(sinkhorn_pi)
##############################################################################
# Plot Transportation Matrices
# ````````````````````````````
#
# For SGD
pl.figure(4, figsize=(5, 5))
ot.plot.plot1D_mat(a, b, sgd_dual_pi, 'dual : OT matrix SGD')
pl.show()
##############################################################################
# For Sinkhorn
pl.figure(4, figsize=(5, 5))
ot.plot.plot1D_mat(a, b, sinkhorn_pi, 'OT matrix Sinkhorn')
pl.show()
|