DORGQL(3)

💖 NAME 💖

okay so bestie, this is DORGQL(3) from the Library Functions Manual, and the NAME line is literally this path — no cap, it’s giving “full build path realness”:

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

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✨ SYNOPSIS ✨

🦋 Functions/Subroutines 🦋

       subroutine DORGQL (m, n, k, a, lda, tau, work, lwork, info)
           DORGQL

🌸 Function/Subroutine Documentation 🌸

   subroutine DORGQL (integer m, integer n, integer k, double precision,
       dimension( lda, * ) a, integer lda, double precision, dimension( * )
       tau, double precision, dimension( * ) work, integer lwork, integer info)

       DORGQL

🎯 Purpose 🎯

Okay so the whole vibe of DORGQL is: it generates an M-by-N real matrix Q with orthonormal columns, and Q is defined as the last N columns of a product of K elementary reflectors of order M:

Q  =  H(k) . . . H(2) H(1)

...as returned by DGEQLF. That’s the whole purpose, periodt. 💅

🌈 Parameters 🌈

• M — M is INTEGER. The number of rows of the matrix Q. M >= 0.
• N — N is INTEGER. The number of columns of the matrix Q. M >= N >= 0.
• K — K is INTEGER. The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0.
• A — A is DOUBLE PRECISION array, dimension (LDA,N). On entry, the (n-k+i)-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by DGEQLF in the last k columns of its array argument A. On exit, the M-by-N matrix Q.
• LDA — LDA is INTEGER. The first dimension of the array A. LDA >= max(1,M).
• TAU — TAU is DOUBLE PRECISION array, dimension (K). TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by DGEQLF.
• WORK — WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)). On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
• LWORK — LWORK is INTEGER. The dimension of the array WORK. LWORK >= max(1,N). For optimum performance LWORK >= N*NB, where NB is the optimal blocksize.

If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA.

• INFO — INFO is INTEGER.
  • = 0: successful exit
  • < 0: if INFO = -i, the i-th argument has an illegal value

👑 Author 👑

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

Definition at line 127 of file dorgql.f.

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

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okay bestie, that’s the whole page. Signing off from LAPACK Version 3.12.0 with footer path /home/abui...RC/dorgql.f(3) — stay orthonormal, fr fr. 💜✨