SRC/zgetc2.f(3)

🎀 NAME 🎀

SRC/zgetc2.f(3) — that's the manual page title, bestie, and the manual name is Library Functions Manual. It's all about one routine, ZGETC2 (zgetc2), and its whole main-character job is computing the LU factorization with complete pivoting of the general n-by-n matrix. Slay. ✨

✨ SYNOPSIS ✨

Functions/Subroutines

• subroutine zgetc2 (n, a, lda, ipiv, jpiv, info) — ZGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

💖 Function/Subroutine Documentation 💖

   subroutine zgetc2 (integer n, complex*16, dimension( lda, * ) a, integer
       lda, integer, dimension( * ) ipiv, integer, dimension( * ) jpiv, integer
       info)

Okay so ZGETC2 computes an LU factorization, using complete pivoting, of the n-by-n matrix A. The factorization has the form A = P * L * U * Q, where P and Q are permutation matrices, L is lower triangular with unit diagonal elements and U is upper triangular.

This is a level 1 BLAS version of the algorithm. Iconic. 👑

🫶 Parameters 🫶

• N — N is INTEGER. It's the order of the matrix A. Constraint: N >= 0.
• A — A is COMPLEX*16 array, dimension (LDA, N). On entry, it's the n-by-n matrix to be factored. On exit, it holds the factors L and U from the factorization A = P*L*U*Q; the unit diagonal elements of L are not stored. If U(k, k) appears to be less than SMIN, U(k, k) is given the value of SMIN, giving a nonsingular perturbed system. 💅
• LDA — LDA is INTEGER. It's the leading dimension of the array A. Constraint: LDA >= max(1, N).
• IPIV — IPIV is INTEGER array, dimension (N). These are the pivot indices; for 1 <= i <= N, row i of the matrix has been interchanged with row IPIV(i).
• JPIV — JPIV is INTEGER array, dimension (N). These are the pivot indices; for 1 <= j <= N, column j of the matrix has been interchanged with column JPIV(j).
• INFO — INFO is INTEGER. Status check, bestie: = 0: successful exit. > 0: if INFO = k, U(k, k) is likely to produce overflow if one tries to solve for x in Ax = b. So U is perturbed to avoid the overflow. 😭

👑 Author 👑

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

🌸 Contributors 🌸

Bo Kagstrom and Peter Poromaa, Department of Computing Science, Umea University, S-901 87 Umea, Sweden.

Definition at line 110 of file zgetc2.f.

💀 Author 💀

Generated automatically by Doxygen for LAPACK from the source code.

---

Catch you later, bestie — this page is LAPACK Version 3.12.0, source SRC/zgetc2.f(3). Mwah 💋✨