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more selective detection of symmetric/hermitian matrices

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This commit is contained in:
conrad
2024-11-28 16:15:56 +11:00
parent b87cc838a3
commit ffb9ef3c52
1 changed files with 20 additions and 5 deletions
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include/armadillo_bits/sym_helper.hpp
+20 -5
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@@ -50,19 +50,26 @@ guess_sympd_worker(const Mat<eT>& A)
const eT* A_mem = A.memptr();
const eT* A_col = A_mem;
bool diag_below_tol = true;
eT max_diag = eT(0);
for(uword j=0; j < N; ++j)
{
const eT A_jj = A_col[j];
if(A_jj <= eT(0)) { return false; }
if( A_jj <= eT(0)) { return false; }
if(arma_isfinite(A_jj) == false) { return false; }
if(A_jj >= tol) { diag_below_tol = false; }
max_diag = (A_jj > max_diag) ? A_jj : max_diag;
A_col += N;
}
if(diag_below_tol) { return false; } // assume matrix is suspect if all diagonal elements are close to zero
A_col = A_mem;
const uword Nm1 = N-1;
@@ -128,6 +135,8 @@ guess_sympd_worker(const Mat<eT>& A)
const eT* A_mem = A.memptr();
const eT* A_col = A_mem;
bool diag_below_tol = true;
T max_diag = T(0);
for(uword j=0; j < N; ++j)
@@ -138,15 +147,21 @@ guess_sympd_worker(const Mat<eT>& A)
const T A_jj_rabs = std::abs(A_jj_r);
const T A_jj_iabs = std::abs(A_jj_i);
if(A_jj_r <= T(0) ) { return false; } // real should be positive
if(A_jj_iabs > tol ) { return false; } // imag should be approx zero
if(A_jj_iabs > A_jj_rabs) { return false; } // corner case: real and imag are close to zero, and imag is dominant
if( A_jj_r <= T(0) ) { return false; } // real should be positive
if(arma_isfinite(A_jj_r) == false) { return false; }
if(A_jj_iabs > tol ) { return false; } // imag should be approx zero
if(A_jj_iabs > A_jj_rabs) { return false; } // corner case: real and imag are close to zero, and imag is dominant
if(A_jj_r >= tol) { diag_below_tol = false; }
max_diag = (A_jj_r > max_diag) ? A_jj_r : max_diag;
A_col += N;
}
if(diag_below_tol) { return false; } // assume matrix is suspect if all diagonal elements are close to zero
const T square_max_diag = max_diag * max_diag;
if(arma_isfinite(square_max_diag) == false) { return false; }
@@ -268,7 +283,7 @@ is_approx_sym_worker(const Mat<eT>& A)
for(uword j=0; j < N; ++j)
{
const eT& A_jj = A_col[j];
const eT A_jj = A_col[j];
if(arma_isfinite(A_jj) == false) { return false; }