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armadillo-code/include/armadillo_bits/op_inv_spd_meat.hpp
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// SPDX-License-Identifier: Apache-2.0
//
// Copyright 2008-2016 Conrad Sanderson (http://conradsanderson.id.au)
// Copyright 2008-2016 National ICT Australia (NICTA)
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ------------------------------------------------------------------------
//! \addtogroup op_inv_spd
//! @{
template<typename T1>
inline
void
op_inv_spd_default::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_inv_spd_default>& X)
{
arma_extra_debug_sigprint();
const bool status = op_inv_spd_default::apply_direct(out, X.m);
if(status == false)
{
out.soft_reset();
arma_stop_runtime_error("inv_sympd(): matrix is singular or not positive definite");
}
}
template<typename T1>
inline
bool
op_inv_spd_default::apply_direct(Mat<typename T1::elem_type>& out, const Base<typename T1::elem_type,T1>& expr)
{
arma_extra_debug_sigprint();
return op_inv_spd::apply_direct<T1,false>(out, expr, uword(0));
}
//
template<typename T1>
inline
void
op_inv_spd::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_inv_spd>& X)
{
arma_extra_debug_sigprint();
const uword flags = X.in_aux_uword_a;
const bool status = op_inv_spd::apply_direct(out, X.m, flags);
if(status == false)
{
out.soft_reset();
arma_stop_runtime_error("inv_sympd(): matrix is singular or not positive definite");
}
}
template<typename T1, const bool has_user_flags>
inline
bool
op_inv_spd::apply_direct(Mat<typename T1::elem_type>& out, const Base<typename T1::elem_type,T1>& expr, const uword flags)
{
arma_extra_debug_sigprint();
typedef typename T1::elem_type eT;
typedef typename T1::pod_type T;
if(has_user_flags == true ) { arma_extra_debug_print("op_inv_spd: has_user_flags = true"); }
if(has_user_flags == false) { arma_extra_debug_print("op_inv_spd: has_user_flags = false"); }
const bool tiny = has_user_flags && bool(flags & inv_opts::flag_tiny );
const bool likely_sympd = has_user_flags && bool(flags & inv_opts::flag_likely_sympd);
const bool no_sympd = has_user_flags && bool(flags & inv_opts::flag_no_sympd );
arma_extra_debug_print("op_inv_gen: enabled flags:");
if(tiny ) { arma_extra_debug_print("tiny"); }
if(likely_sympd) { arma_extra_debug_print("likely_sympd"); }
if(no_sympd ) { arma_extra_debug_print("no_sympd"); }
if(likely_sympd) { arma_debug_warn_level(1, "inv_sympd(): option 'likely_sympd' ignored" ); }
if(no_sympd) { arma_debug_warn_level(1, "inv_sympd(): option 'no_sympd' ignored" ); }
out = expr.get_ref();
arma_debug_check( (out.is_square() == false), "inv_sympd(): given matrix must be square sized" );
if((arma_config::debug) && (auxlib::rudimentary_sym_check(out) == false))
{
if(is_cx<eT>::no ) { arma_debug_warn_level(1, "inv_sympd(): given matrix is not symmetric"); }
if(is_cx<eT>::yes) { arma_debug_warn_level(1, "inv_sympd(): given matrix is not hermitian"); }
}
const uword N = (std::min)(out.n_rows, out.n_cols);
if(tiny && (N <= 4) && (is_cx<eT>::no))
{
arma_extra_debug_print("op_inv_spd: attempting tinymatrix optimisation");
const bool status = op_inv_spd::apply_tiny(out);
if(status) { return true; }
arma_extra_debug_print("op_inv_spd: tinymatrix optimisation failed");
// fallthrough if optimisation failed
}
if(is_cx<eT>::yes)
{
arma_extra_debug_print("op_inv_spd: checking imaginary components of diagonal elements");
const T tol = T(100) * std::numeric_limits<T>::epsilon(); // allow some leeway
const eT* colmem = out.memptr();
for(uword i=0; i<N; ++i)
{
const eT& out_ii = colmem[i];
const T out_ii_imag = access::tmp_imag(out_ii);
if(std::abs(out_ii_imag) > tol) { return false; }
colmem += N;
}
}
if(is_op_diagmat<T1>::value || out.is_diagmat())
{
arma_extra_debug_print("op_inv_spd: detected diagonal matrix");
eT* colmem = out.memptr();
for(uword i=0; i<N; ++i)
{
eT& out_ii = colmem[i];
const T out_ii_real = access::tmp_real(out_ii);
if(out_ii_real <= T(0)) { return false; }
out_ii = eT(T(1) / out_ii_real);
colmem += N;
}
return true;
}
bool sympd_state_junk = false;
return auxlib::inv_sympd(out, sympd_state_junk);
}
template<typename eT>
inline
bool
op_inv_spd::apply_tiny(Mat<eT>& out)
{
arma_extra_debug_sigprint();
typedef typename get_pod_type<eT>::result T;
const uword N = out.n_rows;
if(arma_config::debug)
{
bool print_warning = false;
T max_diag = T(0);
const eT* colmem = out.memptr();
for(uword i=0; i<N; ++i)
{
const eT& out_ii = colmem[i];
const T out_ii_real = access::tmp_real(out_ii);
// NOTE: inv_opts::tiny is also used as a workaround for broken user software
print_warning = (out_ii_real <= T(0)) ? true : print_warning;
max_diag = (out_ii_real > max_diag) ? out_ii_real : max_diag;
colmem += N;
}
colmem = out.memptr();
for(uword c=0; c < N; ++c)
{
for(uword r=(c+1); r < N; ++r)
{
const T abs_val = std::abs(colmem[r]);
print_warning = (abs_val > max_diag) ? true : print_warning;
}
colmem += N;
}
if(print_warning) { arma_debug_warn_level(1, "inv_sympd(): given matrix is not positive definite"); }
}
return op_inv_gen::apply_tiny(out);
}
//! @}