gtsam/geometry/tensorInterface.h

104 lines
3.0 KiB
C++

/*
* tensorInterface.h
* @brief Interfacing tensors template library and gtsam
* Created on: Feb 12, 2010
* @author: Frank Dellaert
*/
#pragma once
#include <gtsam/geometry/tensors.h>
#include <gtsam/base/Matrix.h>
namespace gtsam {
/** Reshape rank 2 tensor into Matrix */
template<class A, class I, class J>
Matrix reshape(const tensors::Tensor2Expression<A, I, J>& T, int m, int n) {
if (m * n != I::dim * J::dim) throw std::invalid_argument(
"reshape: incompatible dimensions");
Matrix M(m, n);
size_t t = 0;
for (int j = 0; j < J::dim; j++)
for (int i = 0; i < I::dim; i++)
M.data()[t++] = T(i, j);
return M;
}
/** Reshape 3*3 rank 2 tensor into Vector : TODO 9 ???*/
template<class A, class I, class J>
Vector toVector(const tensors::Tensor2Expression<A, I, J>& T) {
Vector v(I::dim * J::dim);
size_t t = 0;
for (int j = 0; j < J::dim; j++)
for (int i = 0; i < I::dim; i++)
v(t++) = T(i, j);
return v;
}
/** Reshape Vector into rank 2 tensor */
template<int N1, int N2>
tensors::Tensor2<N1, N2> reshape2(const Vector& v) {
if (v.size() != N1 * N2) throw std::invalid_argument(
"reshape2: incompatible dimensions");
double data[N1][N2];
int t = 0;
for (int j = 0; j < N2; j++)
for (int i = 0; i < N1; i++)
data[j][i] = v(t++);
return tensors::Tensor2<N1, N2>(data);
}
/** Reshape rank 3 tensor into Matrix */
template<class A, class I, class J, class K>
Matrix reshape(const tensors::Tensor3Expression<A, I, J, K>& T, int m, int n) {
if (m * n != I::dim * J::dim * K::dim) throw std::invalid_argument(
"reshape: incompatible dimensions");
Matrix M(m, n);
int t = 0;
for (int k = 0; k < K::dim; k++)
for (int j = 0; j < J::dim; j++)
for (int i = 0; i < I::dim; i++)
M.data()[t++] = T(i, j, k);
return M;
}
/** Reshape Vector into rank 3 tensor */
template<int N1, int N2, int N3>
tensors::Tensor3<N1, N2, N3> reshape3(const Vector& v) {
if (v.size() != N1 * N2 * N3) throw std::invalid_argument(
"reshape3: incompatible dimensions");
double data[N1][N2][N3];
int t = 0;
for (int k = 0; k < N3; k++)
for (int j = 0; j < N2; j++)
for (int i = 0; i < N1; i++)
data[k][j][i] = v(t++);
return tensors::Tensor3<N1, N2, N3>(data);
}
/** Reshape rank 5 tensor into Matrix */
template<class A, class I, class J, class K, class L, class M>
Matrix reshape(const tensors::Tensor5Expression<A, I, J, K, L, M>& T, int m,
int n) {
if (m * n != I::dim * J::dim * K::dim * L::dim * M::dim) throw std::invalid_argument(
"reshape: incompatible dimensions");
Matrix R(m, n);
int t = 0;
for (int m = 0; m < M::dim; m++)
for (int l = 0; l < L::dim; l++)
for (int k = 0; k < K::dim; k++)
for (int j = 0; j < J::dim; j++)
for (int i = 0; i < I::dim; i++)
R.data()[t++] = T(i, j, k, l, m);
return R;
}
/**
* Find Vector v that minimizes algebraic error A*v
* Returns rank of A, minimum error, and corresponding eigenvector
*/
boost::tuple<int,double,Vector> DLT(const Matrix& A);
} // namespace gtsam