https://timsong-cpp.github.io/cppwp/linalg.algs.blas1.givens.lartg
[linalg.algs.blas1.givens.lartg]
linalgalgsgivens
https://www.intel.com/content/www/us/en/docs/onemkl/developer-reference-fortran/2025-2/lartg.html
?lartg
Generates a plane rotation with real cosine and real/complex sine.