SRC/zgetrs.f(3)

📦
version 3.12.1 · 7 versions
, in arch rolling

💖 SRC/zgetrs.f(3) — Library Functions Manual 💖

okay so bestie, this is a page from the LAPACK manual (that's the "Library Functions Manual" vibe, iykyk) and it's all about one little subroutine that is, honestly, kind of a big deal. it's SRC/zgetrs.f and she is ready to solve your systems. let's go ✨

🌸 NAME 🌸

SRC/zgetrs.f — bestie. that's the name. that's the file. slay.

🎀 SYNOPSIS 🎀

Functions/Subroutines

  • subroutine zgetrs (trans, n, nrhs, a, lda, ipiv, b, ldb, info)
    • ZGETRS

🦋 Function/Subroutine Documentation 🦋

subroutine zgetrs (character trans, integer n, integer nrhs, complex*16, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, complex*16, dimension( ldb, * ) b, integer ldb, integer info)

ZGETRS

✨ Purpose ✨

!>
!> ZGETRS solves a system of linear equations
!>    A * X = B,  A**T * X = B,  or  A**H * X = B
!> with a general N-by-N matrix A using the LU factorization computed
!> by ZGETRF.
!>

so basically: she solves your linear system for X, and she does it using the LU factorization that ZGETRF already computed. teamwork makes the dream work, no cap 💅

🌈 Parameters 🌈

  • TRANS — is CHARACTER*1. it tells us which flavor of the system of equations we're dealing with:
!>          TRANS is CHARACTER*1
!>          Specifies the form of the system of equations:
!>          = 'N':  A * X = B     (No transpose)
!>          = 'T':  A**T * X = B  (Transpose)
!>          = 'C':  A**H * X = B  (Conjugate transpose)
!>
  • N — is INTEGER. the order of the matrix A. and N >= 0, periodt.
!>          N is INTEGER
!>          The order of the matrix A.  N >= 0.
!>
  • NRHS — is INTEGER. the number of right hand sides, aka the number of columns of the matrix B. NRHS >= 0, don't forget 🫶
!>          NRHS is INTEGER
!>          The number of right hand sides, i.e., the number of columns
!>          of the matrix B.  NRHS >= 0.
!>
  • A — is COMPLEX*16 array, dimension (LDA,N). she's holding the factors L and U from the factorization A = P*L*U, exactly as computed by ZGETRF. iconic input, honestly.
!>          A is COMPLEX*16 array, dimension (LDA,N)
!>          The factors L and U from the factorization A = P*L*U
!>          as computed by ZGETRF.
!>
  • LDA — is INTEGER. the leading dimension of the array A. and it needs LDA >= max(1,N). rules are rules 💅
!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1,N).
!>
  • IPIV — is INTEGER array, dimension (N). the pivot indices from ZGETRF; for 1<=i<=N, row i of the matrix was interchanged with row IPIV(i). she remembers every swap, fr fr.
!>          IPIV is INTEGER array, dimension (N)
!>          The pivot indices from ZGETRF; for 1<=i<=N, row i of the
!>          matrix was interchanged with row IPIV(i).
!>
  • B — is COMPLEX*16 array, dimension (LDB,NRHS). on entry, this is the right hand side matrix B. on exit, it's the solution matrix X. glow-up of the century, honestly 😭✨
!>          B is COMPLEX*16 array, dimension (LDB,NRHS)
!>          On entry, the right hand side matrix B.
!>          On exit, the solution matrix X.
!>
  • LDB — is INTEGER. the leading dimension of the array B. needs LDB >= max(1,N).
!>          LDB is INTEGER
!>          The leading dimension of the array B.  LDB >= max(1,N).
!>
  • INFO — is INTEGER. the vibe check at the end:
!>          INFO is INTEGER
!>          = 0:  successful exit
!>          < 0:  if INFO = -i, the i-th argument had an illegal value
!>

so 0 means successful exit (we love that for her 🌟), and a negative value means INFO = -i and the i-th argument had an illegal value. rude, but she'll tell you which one 🙈

👑 Author 👑

  • Univ. of Tennessee
  • Univ. of California Berkeley
  • Univ. of Colorado Denver
  • NAG Ltd.

Definition at line 120 of file zgetrs.f.

⭐ Author ⭐

Generated automatically by Doxygen for LAPACK from the source code. she was literally built by the machine, main character energy 🔥

ok that's the whole page bestie, every flag and every caveat is in there, nothing skipped, we don't do that here 💖

LAPACK — Version 3.12.0 🎀 and that's the sign-off, mwah 💋 SRC/zgetrs.f(3), love her, goodbye! 🦋✨

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