elpa_invert_triangular(3)

📦 version 2026.02.002, in nixpkgs unstable

💅 elpa_invert_triangular(3) 💅

okay bestie, this one is straight from the Library Functions Manual, and it’s literally the elpa_invert_triangular(3) page. It’s giving “invert that upper triangular matrix” energy, and we’re gonna keep every single detail. 🫶

✨ NAME ✨

elpa_invert_triangular — inverts an upper triangular matrix. 💖

There are also variations of this routine that can accept not only host but also device pointers as input/output. Names of these routines explicitly contain the corresponding datatypes:

  • elpa_invert_triangular_double
  • elpa_invert_triangular_float
  • elpa_invert_triangular_double_complex
  • elpa_invert_triangular_float_complex

🌸 SYNOPSIS 🌸

🧚 FORTRAN INTERFACE 🧚

use elpa
class(elpa_t), pointer :: elpa_handle

call elpa_handle%invert_triangular (a, error)

With the definitions of the input and output variables:

  • datatype :: a — the local part of the host/device upper triangular matrix A that should be inverted. The dimensions of matrix a must be set BEFORE with the methods elpa_set(3) and elpa_setup(3). The datatype of the matrix can be one of "real(kind=c_double)", "real(kind=c_float)", "complex(kind=c_double)", or "complex(kind=c_float)".
  • integer, optional :: error — the return error code of the function. Should be "ELPA_OK". The error code can be queried with the function elpa_strerr(3).

🦋 C/C++ INTERFACE 🦋

#include <elpa/elpa.h>
elpa_t elpa_handle;

void elpa_invert_triangular(elpa_t elpa_handle, datatype *a, int *error);

With the definitions of the input and output variables:

  • elpa_t elpa_handle; — the handle to the ELPA object.
  • datatype *a; — the local part of the host/device upper triangular matrix A that should be inverted. The dimensions of the matrix must be set BEFORE with the methods elpa_set(3) and elpa_setup(3). The datatype can be one of "double", "float", "double complex"/"std::complex<double>", "float complex"/"std::complex<float>" for C/C++.
  • int *error; — the error code of the function. Should be "ELPA_OK". The error codes can be queried with elpa_strerr(3).

💀 DESCRIPTION 💀

Inverts an upper triangular real or complex matrix. The functions elpa_init(3), elpa_allocate(3), elpa_set(3), and elpa_setup(3) must be called BEFORE elpa_invert_triangular can be called. No cap, that order matters. 🔥

👑 SEE ALSO 👑

mwah 💋 this iconic page comes from ELPA, dated Thu Nov 28 2024, and it’s elpa_invert_triangular(3) — periodt. 🎀

📦 where this page comes from