LAPACK 3.12.0
LAPACK: Linear Algebra PACKage
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subroutine dlaqz1 | ( | double precision, dimension( lda, * ), intent(in) | a, |
integer, intent(in) | lda, | ||
double precision, dimension( ldb, * ), intent(in) | b, | ||
integer, intent(in) | ldb, | ||
double precision, intent(in) | sr1, | ||
double precision, intent(in) | sr2, | ||
double precision, intent(in) | si, | ||
double precision, intent(in) | beta1, | ||
double precision, intent(in) | beta2, | ||
double precision, dimension( * ), intent(out) | v | ||
) |
DLAQZ1
Download DLAQZ1 + dependencies [TGZ] [ZIP] [TXT]
Given a 3-by-3 matrix pencil (A,B), DLAQZ1 sets v to a scalar multiple of the first column of the product (*) K = (A - (beta2*sr2 - i*si)*B)*B^(-1)*(beta1*A - (sr2 + i*si2)*B)*B^(-1). It is assumed that either 1) sr1 = sr2 or 2) si = 0. This is useful for starting double implicit shift bulges in the QZ algorithm.
[in] | A | A is DOUBLE PRECISION array, dimension (LDA,N) The 3-by-3 matrix A in (*). |
[in] | LDA | LDA is INTEGER The leading dimension of A as declared in the calling procedure. |
[in] | B | B is DOUBLE PRECISION array, dimension (LDB,N) The 3-by-3 matrix B in (*). |
[in] | LDB | LDB is INTEGER The leading dimension of B as declared in the calling procedure. |
[in] | SR1 | SR1 is DOUBLE PRECISION |
[in] | SR2 | SR2 is DOUBLE PRECISION |
[in] | SI | SI is DOUBLE PRECISION |
[in] | BETA1 | BETA1 is DOUBLE PRECISION |
[in] | BETA2 | BETA2 is DOUBLE PRECISION |
[out] | V | V is DOUBLE PRECISION array, dimension (N) A scalar multiple of the first column of the matrix K in (*). |
Definition at line 125 of file dlaqz1.f.