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simplifcation: check only one element at bottom-left / top-right

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conrad
2021-12-08 15:47:15 +10:00
parent 189aadca8f
commit 7ccf937a81
1 changed files with 7 additions and 11 deletions
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include/armadillo_bits/trimat_helper.hpp
+7 -11
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@@ -39,19 +39,15 @@ is_triu(const Mat<eT>& A)
if(N < 2) { return false; }
const eT* A_mem = A.memptr();
const eT* A_col = A.memptr();
const eT eT_zero = eT(0);
// quickly check bottom-left corner
const eT* A_col0 = A_mem;
const eT* A_col1 = A_col0 + N;
// quickly check element at bottom-left
if( (A_col0[N-2] != eT_zero) || (A_col0[Nm1] != eT_zero) || (A_col1[Nm1] != eT_zero) ) { return false; }
if(A_col[Nm1] != eT_zero) { return false; }
// if we got to this point, do a thorough check
const eT* A_col = A_mem;
for(uword j=0; j < Nm1; ++j)
{
for(uword i=(j+1); i < N; ++i)
@@ -84,11 +80,11 @@ is_tril(const Mat<eT>& A)
const eT eT_zero = eT(0);
// quickly check top-right corner
const eT* A_colNm2 = A.colptr(N-2);
const eT* A_colNm1 = A_colNm2 + N;
// quickly check element at top-right
if( (A_colNm2[0] != eT_zero) || (A_colNm1[0] != eT_zero) || (A_colNm1[1] != eT_zero) ) { return false; }
const eT* A_colNm1 = A.colptr(N-1);
if(A_colNm1[0] != eT_zero) { return false; }
// if we got to this point, do a thorough check