ZUNT03(3)

okay so bestie, welcome to the ZUNT03(3) page from the Library Functions Manual 💖. This is the LAPACK corner where two unitary matrices get their vibe check, and honestly? it's giving main character energy. ✨

🌸 NAME 🌸

the file is literally right here, no cap: /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/EIG/zunt03.f

✨ SYNOPSIS ✨

🌈 Functions/Subroutines 🌈

here's the call shape, bestie — lowkey iconic:

       subroutine ZUNT03 (rc, mu, mv, n, k, u, ldu, v, ldv, work, lwork, rwork,
           result, info)
           ZUNT03

💅 FUNCTION/SUBROUTINE DOCUMENTATION 💅

and the full signature is highkey this:

   subroutine ZUNT03 (character*( * ) rc, integer mu, integer mv, integer n,
       integer k, complex*16, dimension( ldu, * ) u, integer ldu, complex*16,
       dimension( ldv, * ) v, integer ldv, complex*16, dimension( * ) work,
       integer lwork, double precision, dimension( * ) rwork, double precision
       result, integer info)
       ZUNT03

🎀 Purpose 🎀

okay so what does it actually do? ZUNT03 compares two unitary matrices U and V to see if their corresponding rows or columns span the same spaces. The rows are checked if RC = 'R', and the columns are checked if RC = 'C'. periodt. 💜

RESULT is the maximum of:

| V*V' - I | / ( MV ulp ), if RC = 'R', or

| V'*V - I | / ( MV ulp ), if RC = 'C',

and the maximum over rows (or columns) 1 to K of:

| U(i) - S*V(i) |/ ( N ulp )

where abs(S) = 1 (chosen to minimize the expression), U(i) is the i-th row (column) of U, and V(i) is the i-th row (column) of V. iykyk ✨

🍓 Parameters 🍓

• RC — CHARACTER*1. If RC = 'R' the rows of U and V are to be compared. If RC = 'C' the columns of U and V are to be compared. 🎀
• MU — INTEGER. The number of rows of U if RC = 'R', and the number of columns if RC = 'C'. If MU = 0 ZUNT03 does nothing. MU must be at least zero. ✨
• MV — INTEGER. The number of rows of V if RC = 'R', and the number of columns if RC = 'C'. If MV = 0 ZUNT03 does nothing. MV must be at least zero. 💫
• N — INTEGER. If RC = 'R', the number of columns in the matrices U and V, and if RC = 'C', the number of rows in U and V. If N = 0 ZUNT03 does nothing. N must be at least zero. 🌸
• K — INTEGER. The number of rows or columns of U and V to compare. 0 <= K <= max(MU,MV). 🔥
• U — COMPLEX*16 array, dimension (LDU,N). The first matrix to compare. If RC = 'R', U is MU by N, and if RC = 'C', U is N by MU. 🦋
• LDU — INTEGER. The leading dimension of U. If RC = 'R', LDU >= max(1,MU), and if RC = 'C', LDU >= max(1,N). 👑
• V — COMPLEX*16 array, dimension (LDV,N). The second matrix to compare. If RC = 'R', V is MV by N, and if RC = 'C', V is N by MV. 🌈
• LDV — INTEGER. The leading dimension of V. If RC = 'R', LDV >= max(1,MV), and if RC = 'C', LDV >= max(1,N). ⭐
• WORK — COMPLEX*16 array, dimension (LWORK). 💅
• LWORK — INTEGER. The length of the array WORK. For best performance, LWORK should be at least N*N if RC = 'C' or M*M if RC = 'R', but the tests will be done even if LWORK is 0. 😭
• RWORK — DOUBLE PRECISION array, dimension (max(MV,N)). 🙈
• RESULT — DOUBLE PRECISION. The value computed by the test described above. RESULT is limited to 1/ulp to avoid overflow. 💀
• INFO — INTEGER. 0 indicates a successful exit. -k indicates the k-th parameter had an illegal value. 🫶

👑 Author 👑

shoutout to the author gang — obsessed:

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

Definition at line 160 of file zunt03.f. 💖

🌟 Author 🌟

Generated automatically by Doxygen for LAPACK from the source code. Iconic. 🎀

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and that's the whole page, bestie — you ate! 💖 This was LAPACK Version 3.12.0, from /home/abui...IG/zunt03.f(3) — byeee fr fr! 👑✨