mame/src/lib/netlist/solver/nld_ms_sm.h
2019-10-30 20:42:49 +01:00

304 lines
7.6 KiB
C++

// license:GPL-2.0+
// copyright-holders:Couriersud
/*
* nld_ms_direct.h
*
*
* Sherman-Morrison Solver
*
* Computes the updated inverse of A given that the change in A is
*
* A <- A + (u x v) u,v vectors
*
* In this specific implementation, u is a unit vector specifying the row which
* changed. Thus v contains the changed column.
*
* Than z = A^-1 u , w = transpose(A^-1) v , lambda = v z
*
* A^-1 <- 1.0 / (1.0 + lambda) * (z x w)
*
* The approach is iterative and applied for each row changed.
*
* The performance for a typical circuit like kidniki compared to Gaussian
* elimination is poor:
*
* a) The code needs to be run for each row change.
* b) The inverse of A typically is fully occupied.
*
* It may have advantages for circuits with a high number of elements and only
* few dynamic/active components.
*
*/
#ifndef NLD_MS_SM_H_
#define NLD_MS_SM_H_
#include "nld_matrix_solver.h"
#include "nld_solver.h"
#include "plib/vector_ops.h"
#include <algorithm>
namespace netlist
{
namespace devices
{
template <typename FT, int SIZE>
class matrix_solver_sm_t: public matrix_solver_t
{
friend class matrix_solver_t;
public:
using float_ext_type = FT;
using float_type = FT;
// FIXME: dirty hack to make this compile
static constexpr const std::size_t storage_N = 100;
matrix_solver_sm_t(netlist_state_t &anetlist, const pstring &name,
const analog_net_t::list_t &nets,
const solver_parameters_t *params, const std::size_t size)
: matrix_solver_t(anetlist, name, nets, params)
, m_dim(size)
, m_cnt(0)
{
/* FIXME: Shouldn't be necessary */
for (std::size_t k = 0; k < this->size(); k++)
state().save(*this, RHS(k), this->name(), plib::pfmt("RHS.{1}")(k));
}
void reset() override { matrix_solver_t::reset(); }
protected:
unsigned vsolve_non_dynamic(const bool newton_raphson) override;
unsigned solve_non_dynamic(const bool newton_raphson);
constexpr std::size_t size() const { return m_dim; }
void LE_invert();
template <typename T>
void LE_compute_x(T & x);
template <typename T1, typename T2>
float_ext_type &A(const T1 &r, const T2 &c) { return m_A[r][c]; }
template <typename T1, typename T2>
float_ext_type &W(const T1 &r, const T2 &c) { return m_W[r][c]; }
template <typename T1, typename T2>
float_ext_type &Ainv(const T1 &r, const T2 &c) { return m_Ainv[r][c]; }
template <typename T1>
float_ext_type &RHS(const T1 &r) { return m_RHS[r]; }
template <typename T1, typename T2>
float_ext_type &lA(const T1 &r, const T2 &c) { return m_lA[r][c]; }
template <typename T1, typename T2>
float_ext_type &lAinv(const T1 &r, const T2 &c) { return m_lAinv[r][c]; }
private:
template <typename T, std::size_t N, std::size_t M>
using array2D = std::array<std::array<T, M>, N>;
static constexpr std::size_t m_pitch = ((( storage_N) + 7) / 8) * 8;
array2D<float_ext_type, storage_N, m_pitch> m_A;
array2D<float_ext_type, storage_N, m_pitch> m_Ainv;
array2D<float_ext_type, storage_N, m_pitch> m_W;
std::array<float_ext_type, storage_N> m_RHS; // right hand side - contains currents
array2D<float_ext_type, storage_N, m_pitch> m_lA;
array2D<float_ext_type, storage_N, m_pitch> m_lAinv;
//float_ext_type m_RHSx[storage_N];
const std::size_t m_dim;
std::size_t m_cnt;
};
// ----------------------------------------------------------------------------------------
// matrix_solver_direct
// ----------------------------------------------------------------------------------------
template <typename FT, int SIZE>
void matrix_solver_sm_t<FT, SIZE>::LE_invert()
{
const std::size_t kN = size();
for (std::size_t i = 0; i < kN; i++)
{
for (std::size_t j = 0; j < kN; j++)
{
W(i,j) = lA(i,j) = A(i,j);
Ainv(i,j) = 0.0;
}
Ainv(i,i) = 1.0;
}
/* down */
for (std::size_t i = 0; i < kN; i++)
{
/* FIXME: Singular matrix? */
const float_type f = 1.0 / W(i,i);
const auto * const p = m_terms[i].m_nzrd.data();
const std::size_t e = m_terms[i].m_nzrd.size();
/* Eliminate column i from row j */
const auto * const pb = m_terms[i].m_nzbd.data();
const std::size_t eb = m_terms[i].m_nzbd.size();
for (std::size_t jb = 0; jb < eb; jb++)
{
const unsigned j = pb[jb];
const float_type f1 = - W(j,i) * f;
if (f1 != 0.0)
{
for (std::size_t k = 0; k < e; k++)
W(j,p[k]) += W(i,p[k]) * f1;
for (std::size_t k = 0; k <= i; k ++)
Ainv(j,k) += Ainv(i,k) * f1;
}
}
}
/* up */
for (std::size_t i = kN; i-- > 0; )
{
/* FIXME: Singular matrix? */
const float_type f = 1.0 / W(i,i);
for (std::size_t j = i; j-- > 0; )
{
const float_type f1 = - W(j,i) * f;
if (f1 != 0.0)
{
for (std::size_t k = i; k < kN; k++)
W(j,k) += W(i,k) * f1;
for (std::size_t k = 0; k < kN; k++)
Ainv(j,k) += Ainv(i,k) * f1;
}
}
for (std::size_t k = 0; k < kN; k++)
{
Ainv(i,k) *= f;
lAinv(i,k) = Ainv(i,k);
}
}
}
template <typename FT, int SIZE>
template <typename T>
void matrix_solver_sm_t<FT, SIZE>::LE_compute_x(
T & x)
{
const std::size_t kN = size();
for (std::size_t i=0; i<kN; i++)
x[i] = 0.0;
for (std::size_t k=0; k<kN; k++)
{
const float_type f = RHS(k);
for (std::size_t i=0; i<kN; i++)
x[i] += Ainv(i,k) * f;
}
}
template <typename FT, int SIZE>
unsigned matrix_solver_sm_t<FT, SIZE>::solve_non_dynamic(const bool newton_raphson)
{
static constexpr const bool incremental = true;
const std::size_t iN = size();
// NOLINTNEXTLINE(cppcoreguidelines-pro-type-member-init)
std::array<float_type, storage_N> new_V;
// NOLINTNEXTLINE(cppcoreguidelines-pro-type-member-init)
std::array<float_type, m_pitch> v;
// NOLINTNEXTLINE(cppcoreguidelines-pro-type-member-init)
std::array<std::size_t, m_pitch> cols;
// NOLINTNEXTLINE(cppcoreguidelines-pro-type-member-init)
std::array<float_type, m_pitch> z;
if ((m_cnt % 50) == 0)
{
/* complete calculation */
this->LE_invert();
}
else
{
if (!incremental)
{
for (std::size_t row = 0; row < iN; row ++)
for (std::size_t k = 0; k < iN; k++)
Ainv(row,k) = lAinv(row, k);
}
for (std::size_t row = 0; row < iN; row ++)
{
std::size_t colcount = 0;
auto &nz = m_terms[row].m_nz;
for (unsigned & col : nz)
{
v[col] = A(row,col) - lA(row,col);
if (incremental)
lA(row,col) = A(row,col);
if (v[col] != 0.0)
cols[colcount++] = col;
}
if (colcount > 0)
{
float_type lamba = 0.0;
std::array<float_type, m_pitch> w = {0};
/* compute w and lamba */
for (std::size_t i = 0; i < iN; i++)
z[i] = Ainv(i, row); /* u is row'th column */
for (std::size_t j = 0; j < colcount; j++)
lamba += v[cols[j]] * z[cols[j]];
for (std::size_t j=0; j<colcount; j++)
{
std::size_t col = cols[j];
float_type f = v[col];
for (std::size_t k = 0; k < iN; k++)
w[k] += Ainv(col,k) * f; /* Transpose(Ainv) * v */
}
lamba = -1.0 / (1.0 + lamba);
for (std::size_t i=0; i<iN; i++)
{
const float_type f = lamba * z[i];
if (f != 0.0)
for (std::size_t k = 0; k < iN; k++)
Ainv(i,k) += f * w[k];
}
}
}
}
m_cnt++;
this->LE_compute_x(new_V);
const float_type err = (newton_raphson ? delta(new_V) : 0.0);
store(new_V);
return (err > this->m_params.m_accuracy) ? 2 : 1;
}
template <typename FT, int SIZE>
unsigned matrix_solver_sm_t<FT, SIZE>::vsolve_non_dynamic(const bool newton_raphson)
{
this->build_LE_A(*this);
this->build_LE_RHS(*this);
this->m_stat_calculations++;
return this->solve_non_dynamic(newton_raphson);
}
} // namespace devices
} // namespace netlist
#endif /* NLD_MS_DIRECT_H_ */