T LpIneq(size_t m, size_t n) {
std::vector<T> A(m * n);
std::vector<T> x(n);
std::vector<T> y(m);
std::default_random_engine generator;
std::uniform_real_distribution<T> u_dist(static_cast<T>(0),
static_cast<T>(1));
// Generate A according to:
// A = [-1 / n *rand(m - n, n); -eye(n)]
for (unsigned int i = 0; i < (m - n) * n; ++i)
A[i] = -static_cast<T>(1) / static_cast<T>(n) * u_dist(generator);
for (unsigned int i = static_cast<unsigned int>((m - n) * n); i < m * n; ++i)
A[i] = (i - (m - n) * n) % (n + 1) == 0 ? -1 : 0;
PogsData<T, T*> pogs_data(A.data(), m, n);
pogs_data.x = x.data();
pogs_data.y = y.data();
// Generate b according to:
// b = A * rand(n, 1) + 0.2 * rand(m, 1)
pogs_data.f.reserve(m);
for (unsigned int i = 0; i < m; ++i) {
T b_i = static_cast<T>(0);
for (unsigned int j = 0; j < n; ++j)
b_i += A[i * n + j] * u_dist(generator);
b_i += static_cast<T>(0.2) * u_dist(generator);
pogs_data.f.emplace_back(kIndLe0, static_cast<T>(1), b_i);
}
// Generate c according to:
// c = rand(n, 1)
pogs_data.g.reserve(n);
for (unsigned int i = 0; i < n; ++i)
pogs_data.g.emplace_back(kIdentity, u_dist(generator));
T t = timer<T>();
Pogs(&pogs_data);
return timer<T>() - t;
}
void SolverWrap(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[]) {
size_t m = mxGetM(prhs[0]);
size_t n = mxGetN(prhs[0]);
// Convert column major (matlab) to row major (c++).
T* A = new T[m * n];
ColToRowMajor(reinterpret_cast<T*>(mxGetPr(prhs[0])), m, n, A);
// Initialize Pogs data structure
PogsData<T, T*> pogs_data(A, m, n);
pogs_data.f.reserve(m);
pogs_data.g.reserve(n);
pogs_data.x = reinterpret_cast<T*>(mxGetPr(plhs[0]));
if (nlhs >= 2)
pogs_data.y = reinterpret_cast<T*>(mxGetPr(plhs[1]));
// Populate parameters.
int err = 0;
if (nrhs == 4)
err = PopulateParams(prhs[3], &pogs_data);
// Populate function objects.
if (err == 0)
err = PopulateFunctionObj("f", prhs[1], m, &pogs_data.f);
if (err == 0)
err = PopulateFunctionObj("g", prhs[2], n, &pogs_data.g);
// Run solver.
if (err == 0)
Pogs(&pogs_data);
if (nlhs >= 3)
reinterpret_cast<T*>(mxGetPr(plhs[2]))[0] = pogs_data.optval;
delete [] A;
}
double Logistic(size_t m, size_t n) {
std::vector<T> A(m * (n + 1));
std::vector<T> d(m);
std::vector<T> x(n + 1);
std::vector<T> y(m);
std::default_random_engine generator;
std::uniform_real_distribution<T> u_dist(static_cast<T>(0),
static_cast<T>(1));
std::normal_distribution<T> n_dist(static_cast<T>(0),
static_cast<T>(1));
for (unsigned int i = 0; i < m; ++i) {
for (unsigned int j = 0; j < n; ++j)
A[i * (n + 1) + j] = n_dist(generator);
A[i * (n + 1) + n] = 1;
}
std::vector<T> x_true(n + 1);
for (unsigned int i = 0; i < n; ++i)
x_true[i] = u_dist(generator) < 0.8 ? 0 : n_dist(generator) / n;
x_true[n] = n_dist(generator) / n;
#pragma omp parallel for
for (unsigned int i = 0; i < m; ++i) {
d[i] = 0;
for (unsigned int j = 0; j < n + 1; ++j)
// u += A[i + j * m] * x_true[j];
d[i] += A[i * n + j] * x_true[j];
}
for (unsigned int i = 0; i < m; ++i)
d[i] = 1 / (1 + std::exp(-d[i])) > u_dist(generator);
T lambda_max = static_cast<T>(0);
#pragma omp parallel for reduction(max : lambda_max)
for (unsigned int j = 0; j < n; ++j) {
T u = 0;
for (unsigned int i = 0; i < m; ++i)
// u += A[i * n + j] * (static_cast<T>(0.5) - d[i]);
u += A[i + j * m] * (static_cast<T>(0.5) - d[i]);
lambda_max = std::max(lambda_max, std::abs(u));
}
Dense<T, ROW> A_(A.data());
PogsData<T, Dense<T, ROW>> pogs_data(A_, m, n + 1);
pogs_data.x = x.data();
pogs_data.y = y.data();
pogs_data.f.reserve(m);
for (unsigned int i = 0; i < m; ++i)
pogs_data.f.emplace_back(kLogistic, 1, 0, 1, -d[i]);
pogs_data.g.reserve(n + 1);
for (unsigned int i = 0; i < n; ++i)
pogs_data.g.emplace_back(kAbs, static_cast<T>(0.5) * lambda_max);
pogs_data.g.emplace_back(kZero);
double t = timer<double>();
Pogs(&pogs_data);
return timer<double>() - t;
}
