Kokkos Node API and Local Linear Algebra Kernels Version of the Day
|static bool||QR_produces_R_factor_with_nonnegative_diagonal ()|
|Does the R factor have a nonnegative diagonal? |
Interface to Fortran 9x back end of
TSQR::Combine has three implementations: CombineDefault, CombineNative, and CombineFortran. The latter, implemented in this file, is a C++ front end to a Fortran 9x implementation. CombineFortran is not templated on the Ordinal type, because the Fortran implementation uses int for that.
|static bool TSQR::CombineFortran< Scalar, is_complex >::QR_produces_R_factor_with_nonnegative_diagonal||(||)||
Does the R factor have a nonnegative diagonal?
CombineFortran implements a QR factorization (of a matrix with a special structure). Some, but not all, QR factorizations produce an R factor whose diagonal may include negative entries. This Boolean tells you whether CombineFortran promises to compute an R factor whose diagonal entries are all nonnegative.