There is one prototype of tgsyl
available, please see below.
tgsyl( const int_t ijob, const MatrixA& a, const MatrixB& b, MatrixC& c, const MatrixD& d, const MatrixE& e, MatrixF& f, Scalar >, Scalar > );
tgsyl (short for $FRIENDLY_NAME)
provides a C++ interface to LAPACK routines STGSYL, DTGSYL, CTGSYL, and
ZTGSYL. tgsyl solves
the generalized Sylvester equation:
A * R - L * B = scale * C (1) D * R - L * E = scale * F
where R and L are unknown m-by-n matrices, (A, D), (B, E) and (C, F) are given matrix pairs of size m-by-m, n-by-n and m-by-n, respectively, with complex entries. A, B, D and E are upper triangular (i.e., (A,D) and (B,E) in generalized Schur form).
The solution (R, L) overwrites (C, F). 0 <= SCALE <= 1 is an output scaling factor chosen to avoid overflow.
In matrix notation (1) is equivalent to solve Zx = scale*b, where Z is defined as
Z = [ kron(In, A) -kron(B', Im) ] (2) [ kron(In, D) -kron(E', Im) ],
Here Ix is the identity matrix of size x and X' is the conjugate transpose of X. Kron(X, Y) is the Kronecker product between the matrices X and Y.
If TRANS = 'C', y in the conjugate transposed system Z'*y = scale*b is solved for, which is equivalent to solve for R and L in
A' * R + D' * L = scale * C (3) R * B' + L * E' = scale * -F
This case (TRANS = 'C') is used to compute an one-norm-based estimate of Dif[(A,D), (B,E)], the separation between the matrix pairs (A,D) and (B,E), using ZLACON.
If IJOB >= 1, tgsyl
computes a Frobenius norm-based estimate of Dif[(A,D),(B,E)]. That is,
the reciprocal of a lower bound on the reciprocal of the smallest singular
value of Z.
This is a level-3 BLAS algorithm.
The selection of the LAPACK routine is done during compile-time, and
is determined by the type of values contained in type MatrixA.
The type of values is obtained through the value_type
meta-function typename value_type<MatrixA>::type. The dispatching table below illustrates
to which specific routine the code path will be generated.
Table 1.338. Dispatching of tgsyl
|
Value type of MatrixA |
LAPACK routine |
|---|---|
|
|
STGSYL |
|
|
DTGSYL |
|
|
CTGSYL |
|
|
ZTGSYL |
Defined in header boost/numeric/bindings/lapack/computational/tgsyl.hpp.
Parameters
The definition of term 1
The definition of term 2
The definition of term 3.
Definitions may contain paragraphs.
#include <boost/numeric/bindings/lapack/computational/tgsyl.hpp> using namespace boost::numeric::bindings; lapack::tgsyl( x, y, z );
this will output
[5] 0 1 2 3 4 5