Re: [Gretl-devel] c code question

On Sun, 15 Oct 2017, oleg_komashko(a)ukr.net wrote: If your thoughts tend in the direction of complex matrices, maybe I should point out that we have a few "hidden" hansl functions for complex operations. They're hidden because we don't have a native complex-matrix type, and also because the API is still negotiable, but... our current internal representation of an m x n complex matrix is a 2*m x n gretl matrix, where the doubling of the number of rows means that each complex element occupies two rows (real, then imaginary). The functions available are (yes, the leading underscore is part of the name): _ceigh: eigen-decomposition of complex (Hermitian) matrix _cinv: inverse of a complex matrix via LU decomposition _cmmult: multiplication of complex matrices _chprod: Hadamard product of complex matrices _cmatrix: compose a complex matrix from its real and imaginary component matrices _cfft: complex Fourier transform _cxtract: extract the real or complex part of a complex matrix _ctran: conjugate transpose of complex matrix You can inspect the C code in lib/src/gretl_cmatrix.c. We use OpenBLAS functionality for the more substantial operations. Allin