CTREXC(3)

CTREXC(3) — Library Functions Manual 🦋

okay bestie, this is the Library Functions Manual page for CTREXC, and we're gonna get you comfy with it. no cap. 💅

💖 NAME 💖

The name on this page is literally this path:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/ctrexc.f

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

   subroutine CTREXC (compq, n, t, ldt, q, ldq, ifst, ilst, info)
       CTREXC

🦋 Function/Subroutine Documentation 🦋

   subroutine CTREXC (character compq, integer n, complex, dimension( ldt, * )
       t, integer ldt, complex, dimension( ldq, * ) q, integer ldq, integer
       ifst, integer ilst, integer info)
       CTREXC

🎀 Purpose: 🎀

okay so CTREXC reorders the Schur factorization of a complex matrix A = Q*T*Q**H, so that the diagonal element of T with row index IFST is moved to row ILST. The Schur form T is reordered by a unitary similarity transformation Z**H*T*Z, and optionally the matrix Q of Schur vectors is updated by postmultiplying it with Z. 💅

🌈 Parameters 🌈

• COMPQ — is CHARACTER*1. = 'V': update the matrix Q of Schur vectors; = 'N': do not update Q. 👑
• N — is INTEGER. The order of the matrix T. N >= 0. If N == 0 arguments ILST and IFST may be any value. 🫶
• T — is COMPLEX array, dimension (LDT,N). On entry, the upper triangular matrix T. On exit, the reordered upper triangular matrix. ✨
• LDT — is INTEGER. The leading dimension of the array T. LDT >= max(1,N). 💅
• Q — is COMPLEX array, dimension (LDQ,N). On entry, if COMPQ = 'V', the matrix Q of Schur vectors. On exit, if COMPQ = 'V', Q has been postmultiplied by the unitary transformation matrix Z which reorders T. If COMPQ = 'N', Q is not referenced. 🦋
• LDQ — is INTEGER. The leading dimension of the array Q. LDQ >= 1, and if COMPQ = 'V', LDQ >= max(1,N). 🌸
• IFST — is INTEGER. 🎀
• ILST — is INTEGER. Specify the reordering of the diagonal elements of T: The element with row index IFST is moved to row ILST by a sequence of transpositions between adjacent elements. 1 <= IFST <= N; 1 <= ILST <= N. 🔥
• INFO — is INTEGER. = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. 💀

👑 Author 👑

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

📌 Definition at line 125 of file ctrexc.f. 📌

🫶 Author 🫶

Generated automatically by Doxygen for LAPACK from the source code.

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Footer vibe check: LAPACK Version 3.12.0 and /home/abui...RC/ctrexc.f(3). That's the source/version + path sign-off, bestie. Slay, periodt. 💅✨🎀