ZLAQSP(3)

💅 ZLAQSP(3) — Library Functions Manual ✨

NAME 🎀

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/zlaqsp.f — this is the source file, bestie. The NAME section is literally just that path, and honestly? iconic. 💖

🌸 SYNOPSIS 🌸

Functions/Subroutines ✨

• subroutine ZLAQSP (uplo, n, ap, s, scond, amax, equed) — ZLAQSP scales a symmetric/Hermitian matrix in packed storage, using scaling factors computed by sppequ.

💖 Function/Subroutine Documentation 💖

   subroutine ZLAQSP (character uplo, integer n, complex*16, dimension( * ) ap,
       double precision, dimension( * ) s, double precision scond, double
       precision amax, character equed)

ZLAQSP scales a symmetric/Hermitian matrix in packed storage, using scaling factors computed by sppequ. No cap, that's the whole job. 🫶

Purpose 🎯

ZLAQSP equilibrates a symmetric matrix A using the scaling factors in the vector S. Slay, honestly. 💅

Parameters 🧚

UPLO 🦋

• Type: CHARACTER*1
• What it does: tells us whether the upper or lower triangular part of the symmetric matrix A is stored.
• = 'U': Upper triangular
• = 'L': Lower triangular

N 🐚

• Type: INTEGER
• What it does: the order of the matrix A. Requirement: N >= 0.

bestie, N >= 0 is a hard requirement, not a vibe suggestion 💀

AP 🫧

• Type: COMPLEX*16 array, dimension (N*(N+1)/2)
• On entry: the upper or lower triangle of the symmetric matrix A, packed columnwise in a linear array. The j-th column of A is stored in the array AP like this:
  • if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
  • if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.
• On exit: the equilibrated matrix diag(S) * A * diag(S), in the same storage format as A.

S 🍓

• Type: DOUBLE PRECISION array, dimension (N)
• What it does: the scale factors for A.

SCOND ⭐

• Type: DOUBLE PRECISION
• What it does: ratio of the smallest S(i) to the largest S(i).

AMAX 🔥

• Type: DOUBLE PRECISION
• What it does: absolute value of largest matrix entry.

EQUED 💅

• Type: CHARACTER*1
• What it does: specifies whether or not equilibration was done.
• = 'N': No equilibration.
• = 'Y': Equilibration was done, i.e., A has been replaced by diag(S) * A * diag(S).

Internal Parameters ⚙️

• THRESH is a threshold value used to decide if scaling should be done based on the ratio of the scaling factors. If SCOND < THRESH, scaling is done.
• LARGE and SMALL are threshold values used to decide if scaling should be done based on the absolute size of the largest matrix element. If AMAX > LARGE or AMAX < SMALL, scaling is done.

Author 👑

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

Definition at line 125 of file zlaqsp.f.

Author 🫶

Generated automatically by Doxygen for LAPACK from the source code.

💖 That's the whole page: LAPACK Version 3.12.0, from /home/abui...RC/zlaqsp.f(3). Bye bestie — go slay that packed symmetric matrix! 💅✨