SRC/zlaqz1.f(3) Library Functions Manual SRC/zlaqz1.f(3) NAME SRC/zlaqz1.f SYNOPSIS Functions/Subroutines subroutine zlaqz1 (ilq, ilz, k, istartm, istopm, ihi, a, lda, b, ldb, nq, qstart, q, ldq, nz, zstart, z, ldz) ZLAQZ1 Function/Subroutine Documentation subroutine zlaqz1 (logical, intent(in) ilq, logical, intent(in) ilz, integer, intent(in) k, integer, intent(in) istartm, integer, intent(in) istopm, integer, intent(in) ihi, complex*16, dimension( lda, * ) a, integer, intent(in) lda, complex*16, dimension( ldb, * ) b, integer, intent(in) ldb, integer, intent(in) nq, integer, intent(in) qstart, complex*16, dimension( ldq, * ) q, integer, intent(in) ldq, integer, intent(in) nz, integer, intent(in) zstart, complex*16, dimension( ldz, * ) z, integer, intent(in) ldz) ZLAQZ1 Purpose: ZLAQZ1 chases a 1x1 shift bulge in a matrix pencil down a single position Parameters ILQ ILQ is LOGICAL Determines whether or not to update the matrix Q ILZ ILZ is LOGICAL Determines whether or not to update the matrix Z K K is INTEGER Index indicating the position of the bulge. On entry, the bulge is located in (A(k+1,k),B(k+1,k)). On exit, the bulge is located in (A(k+2,k+1),B(k+2,k+1)). ISTARTM ISTARTM is INTEGER ISTOPM ISTOPM is INTEGER Updates to (A,B) are restricted to (istartm:k+2,k:istopm). It is assumed without checking that istartm <= k+1 and k+2 <= istopm IHI IHI is INTEGER A A is COMPLEX*16 array, dimension (LDA,N) LDA LDA is INTEGER The leading dimension of A as declared in the calling procedure. B B is COMPLEX*16 array, dimension (LDB,N) LDB LDB is INTEGER The leading dimension of B as declared in the calling procedure. NQ NQ is INTEGER The order of the matrix Q QSTART QSTART is INTEGER Start index of the matrix Q. Rotations are applied To columns k+2-qStart:k+3-qStart of Q. Q Q is COMPLEX*16 array, dimension (LDQ,NQ) LDQ LDQ is INTEGER The leading dimension of Q as declared in the calling procedure. NZ NZ is INTEGER The order of the matrix Z ZSTART ZSTART is INTEGER Start index of the matrix Z. Rotations are applied To columns k+1-qStart:k+2-qStart of Z. Z Z is COMPLEX*16 array, dimension (LDZ,NZ) LDZ LDZ is INTEGER The leading dimension of Q as declared in the calling procedure. Author Thijs Steel, KU Leuven Date May 2020 Definition at line 171 of file zlaqz1.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 SRC/zlaqz1.f(3)