File: sdmm.cc

package info (click to toggle)
sopt 5.0.1%2Bdfsg-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 6,704 kB
  • sloc: cpp: 13,620; xml: 182; makefile: 6
file content (233 lines) | stat: -rw-r--r-- 9,025 bytes parent folder | download | duplicates (2)
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
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
#include <catch2/catch_all.hpp>
#include <random>

#include <Eigen/Dense>

#include "sopt/proximal.h"
#include "sopt/sdmm.h"
#include "sopt/types.h"

sopt::t_int random_integer(sopt::t_int min, sopt::t_int max) {
  extern std::unique_ptr<std::mt19937_64> mersenne;
  std::uniform_int_distribution<sopt::t_int> uniform_dist(min, max);
  return uniform_dist(*mersenne);
};

using Scalar = sopt::t_real;
using t_Vector = sopt::Vector<Scalar>;
using t_Matrix = sopt::Matrix<Scalar>;

auto constexpr N = 4;

// Makes members public so we can test one at a time
class IntrospectSDMM : public sopt::algorithm::SDMM<Scalar> {
 public:
  using sopt::algorithm::SDMM<Scalar>::initialization;
  using sopt::algorithm::SDMM<Scalar>::solve_for_xn;
  using sopt::algorithm::SDMM<Scalar>::update_directions;
  using sopt::algorithm::SDMM<Scalar>::t_Vectors;
  using sopt::algorithm::SDMM<Scalar>::t_Vector;
};

TEST_CASE("Proximal translation", "[proximal]") {
  using namespace sopt;
  t_Vector const translation = t_Vector::Ones(N) * 5;
  auto const g = proximal::EuclidianNorm();
  auto const gT = proximal::translate(g, -translation);
  t_Vector const input = t_Vector::Random(N).array() + 1e0;
  CHECK(g(0.1, input).isApprox((1e0 - 0.1 / input.stableNorm()) * input));
  auto const gamma = input.stableNorm() * 0.5;
  CHECK(g(gamma, input).isApprox((1e0 - gamma / input.stableNorm()) * input));
  CHECK(g(gamma * 2 + 1, input).isApprox(input.Zero(N)));
  CHECK(gT(0.1, input)
            .isApprox((1e0 - 0.1 / (input - translation).stableNorm()) * (input - translation) +
                      translation));
}

// Iterate through algorithm for special case where the L_i are identies and the objective functions
// are simple euclidian norms
TEST_CASE("Introspect SDMM with L_i = Identity and Euclidian objectives", "[sdmm]") {
  using namespace sopt;

  t_Matrix const Id = t_Matrix::Identity(N, N).eval();
  t_Vector const target0 = t_Vector::Zero(N);
  t_Vector const target1 = t_Vector::Random(N);

  auto const g0 = proximal::translate(proximal::EuclidianNorm(), -target0);
  auto const g1 = proximal::translate(proximal::EuclidianNorm(), -target1);
  t_Vector const input = 10 * t_Vector::Random(N);

  IntrospectSDMM sdmm = IntrospectSDMM();
  sdmm.itermax(10)
      .gamma(0.01)
      .conjugate_gradient(std::numeric_limits<t_uint>::max(), 1e-12)
      .append(g0, Id)
      .append(g1, Id);

  SECTION("Step by Step") {
    INFO("Initialization");
    t_Vector out = input;
    IntrospectSDMM::t_Vectors y(sdmm.transforms().size(), t_Vector::Zero(out.size()));
    IntrospectSDMM::t_Vectors z(sdmm.transforms().size(), t_Vector::Zero(out.size()));
    sdmm.initialization(y, z, out);
    CHECK(y[0].isApprox(input));
    CHECK(y[1].isApprox(input));

    INFO("\nThen solve for conjugate gradient");
    auto const diagnostic0 = sdmm.solve_for_xn(out, y, z);
    CHECK(diagnostic0.good);
    CAPTURE(out.transpose());
    CAPTURE(input.transpose());
    CAPTURE(0.5 * (y[0] + y[1]).transpose());
    CHECK(out.isApprox(0.5 * (y[0] + y[1]), 1e-8));
    CHECK(out.isApprox(input, 1e-8));

    INFO("\nWe move on to first iteration!");
    INFO("- updates y and z");
    sdmm.update_directions(y, z, out);
    CHECK(y[0].isApprox(g0(sdmm.gamma(), input)));
    CHECK(y[1].isApprox(g1(sdmm.gamma(), input)));
    CHECK(z[0].isApprox(input - y[0]));
    CHECK(z[1].isApprox(input - y[1]));

    INFO("- solve for conjugate gradient");
    auto const diagnostic1 = sdmm.solve_for_xn(out, y, z);
    CHECK(diagnostic1.good);
    CAPTURE(out.transpose());
    CAPTURE((0.5 * (y[0] - z[0] + y[1] - z[1])).transpose());
    CHECK(out.isApprox(0.5 * (y[0] - z[0] + y[1] - z[1])));
    t_Vector const x1 = g0(sdmm.gamma(), input) + g1(sdmm.gamma(), input) - input;
    CHECK(out.isApprox(x1));

    INFO("\nWe move on to second iteration!");
    INFO("- updates y and z");
    sdmm.update_directions(y, z, out);
    CHECK(y[0].isApprox(g0(sdmm.gamma(), g1(sdmm.gamma(), input))));
    CHECK(y[1].isApprox(g1(sdmm.gamma(), g0(sdmm.gamma(), input))));
    CHECK(z[0].isApprox(g1(sdmm.gamma(), input) - y[0]));
    CHECK(z[1].isApprox(g0(sdmm.gamma(), input) - y[1]));

    INFO("- solve for conjugate gradient");
    auto const diagnostic2 = sdmm.solve_for_xn(out, y, z);
    CHECK(diagnostic2.good);
    CHECK(out.isApprox(0.5 * (y[0] - z[0] + y[1] - z[1])));
    t_Vector const x2 = g0(sdmm.gamma(), g1(sdmm.gamma(), input)) +
                        g1(sdmm.gamma(), g0(sdmm.gamma(), input)) - 0.5 * g1(sdmm.gamma(), input) -
                        0.5 * g0(sdmm.gamma(), input);
    CHECK(out.isApprox(x2));
  }

  SECTION("Iteration by Iteration") {
    t_Vector out;
    SECTION("First Iteration") {
      sdmm.itermax(1);
      auto const diagnostic = sdmm(out, input);
      CHECK(not diagnostic.good);
      CHECK(diagnostic.niters == 1);
      CHECK(out.isApprox(g0(sdmm.gamma(), input) + g1(sdmm.gamma(), input) - input));
    }
    SECTION("Second Iteration") {
      sdmm.itermax(2);
      auto const diagnostic = sdmm(out, input);
      CHECK(not diagnostic.good);
      CHECK(diagnostic.niters == 2);
      t_Vector const x2 = g0(sdmm.gamma(), g1(sdmm.gamma(), input)) +
                          g1(sdmm.gamma(), g0(sdmm.gamma(), input)) -
                          0.5 * g1(sdmm.gamma(), input) - 0.5 * g0(sdmm.gamma(), input);
      CHECK(out.isApprox(x2));
    }

    SECTION("Nth Iterations") {
      sdmm.gamma(1);
      for (t_uint itermax(0); itermax < 10; ++itermax) {
        t_Vector x = input;
        t_Vector y[2] = {x, x};
        t_Vector z[2] = {t_Vector::Zero(N).eval(), t_Vector::Zero(N).eval()};
        for (t_uint i(0); i < itermax; ++i) {
          y[0] = g0(sdmm.gamma(), x + z[0]);
          y[1] = g1(sdmm.gamma(), x + z[1]);
          z[0] += x - g0(sdmm.gamma(), x + z[0]);
          z[1] += x - g1(sdmm.gamma(), x + z[1]);
          x = 0.5 * (y[0] - z[0] + y[1] - z[1]);
        }

        sdmm.itermax(itermax);
        auto const diagnostic = sdmm(out, input);
        CHECK(out.isApprox(x, 1e-8));
        CHECK(not diagnostic.good);
        CHECK(diagnostic.niters == itermax);
      }
    }
  }
}

TEST_CASE("SDMM with ||x - x0||_2 functions", "[sdmm][integration]") {
  using namespace sopt;

  t_Matrix const Id = t_Matrix::Identity(N, N).eval();
  t_Vector const target0 = t_Vector::Random(N);
  t_Vector target1 = t_Vector::Random(N) * 4;
  // for(t_uint i(0); i < N; ++i) target1(i) = i + 1;

  auto sdmm = algorithm::SDMM<Scalar>()
                  .itermax(5000)
                  .gamma(1)
                  .conjugate_gradient(std::numeric_limits<t_uint>::max(), 1e-12)
                  .append(proximal::translate(proximal::EuclidianNorm(), -target0), Id)
                  .append(proximal::translate(proximal::EuclidianNorm(), -target1), Id);

  t_Vector result;
  SECTION("Just two operators") {
    auto const diagnostic = sdmm(result, t_Vector::Random(N));
    CHECK(not diagnostic.good);
    CHECK(diagnostic.niters == sdmm.itermax());
    t_Vector const segment = (target1 - target0).normalized();
    t_real const alpha = (result - target0).transpose() * segment;
    CAPTURE(target0.transpose());
    CAPTURE(target1.transpose());
    CHECK((target1 - target0).transpose() * segment >= alpha);
    CHECK(alpha >= 0e0);
    CHECK((result - target0 - alpha * segment).stableNorm() < 1e-8);
  }

  SECTION("Three operators") {
    t_Vector const target2 = t_Vector::Random(N) * 8;
    sdmm.append(proximal::translate(proximal::EuclidianNorm(), -target2), Id);
    auto const diagnostic = sdmm(result, t_Vector::Random(N));
    CHECK(not diagnostic.good);
    CHECK(diagnostic.niters == sdmm.itermax());
    CAPTURE(result.transpose());
    auto const func = [&target0, &target1, &target2](t_Vector const &x) {
      return (x - target0).stableNorm() + (x - target1).stableNorm() + (x - target2).stableNorm();
    };
    for (int i(0); i < N; ++i) {
      t_Vector epsilon = t_Vector::Zero(N);
      epsilon(i) = 1e-6;
      CHECK(func(result) < func(result + epsilon));
      CHECK(func(result) < func(result - epsilon));
    }
  }

  SECTION("With different L") {
    t_Matrix const L0 = t_Matrix::Random(N, N) * 2;
    t_Matrix const L1 = t_Matrix::Random(N, N) * 4;
    REQUIRE(std::abs((L0.transpose() * L0 + L1.transpose() * L1).determinant()) > 1e-8);
    sdmm.itermax(300);
    sdmm.transforms(0) = linear_transform(L0);
    sdmm.transforms(1) = linear_transform(L1);
    auto const diagnostic = sdmm(result, t_Vector::Random(N));
    CHECK(not diagnostic.good);
    CHECK(diagnostic.niters == sdmm.itermax());
    CAPTURE(result.transpose());
    auto const func = [&target0, &target1, &L0, &L1](t_Vector const &x) {
      return (L0 * x - target0).stableNorm() + (L1 * x - target1).stableNorm();
    };
    for (int i(0); i < N; ++i) {
      t_Vector epsilon = t_Vector::Zero(N);
      epsilon(i) = 1e-3;
      CAPTURE(epsilon.transpose());
      CHECK(func(result) <= func(result + epsilon));
      CHECK(func(result) <= func(result - epsilon));
    }
  }
}