org.netlib.lapack
Class STRSYL
java.lang.Object
org.netlib.lapack.STRSYL
public class STRSYL
- extends java.lang.Object
STRSYL is a simplified interface to the JLAPACK routine strsyl.
This interface converts Java-style 2D row-major arrays into
the 1D column-major linearized arrays expected by the lower
level JLAPACK routines. Using this interface also allows you
to omit offset and leading dimension arguments. However, because
of these conversions, these routines will be slower than the low
level ones. Following is the description from the original Fortran
source. Contact seymour@cs.utk.edu with any questions.
* ..
*
* Purpose
* =======
*
* STRSYL solves the real Sylvester matrix equation:
*
* op(A)*X + X*op(B) = scale*C or
* op(A)*X - X*op(B) = scale*C,
*
* where op(A) = A or A**T, and A and B are both upper quasi-
* triangular. A is M-by-M and B is N-by-N; the right hand side C and
* the solution X are M-by-N; and scale is an output scale factor, set
* <= 1 to avoid overflow in X.
*
* A and B must be in Schur canonical form (as returned by SHSEQR), that
* is, block upper triangular with 1-by-1 and 2-by-2 diagonal blocks;
* each 2-by-2 diagonal block has its diagonal elements equal and its
* off-diagonal elements of opposite sign.
*
* Arguments
* =========
*
* TRANA (input) CHARACTER*1
* Specifies the option op(A):
* = 'N': op(A) = A (No transpose)
* = 'T': op(A) = A**T (Transpose)
* = 'C': op(A) = A**H (Conjugate transpose = Transpose)
*
* TRANB (input) CHARACTER*1
* Specifies the option op(B):
* = 'N': op(B) = B (No transpose)
* = 'T': op(B) = B**T (Transpose)
* = 'C': op(B) = B**H (Conjugate transpose = Transpose)
*
* ISGN (input) INTEGER
* Specifies the sign in the equation:
* = +1: solve op(A)*X + X*op(B) = scale*C
* = -1: solve op(A)*X - X*op(B) = scale*C
*
* M (input) INTEGER
* The order of the matrix A, and the number of rows in the
* matrices X and C. M >= 0.
*
* N (input) INTEGER
* The order of the matrix B, and the number of columns in the
* matrices X and C. N >= 0.
*
* A (input) REAL array, dimension (LDA,M)
* The upper quasi-triangular matrix A, in Schur canonical form.
*
* LDA (input) INTEGER
* The leading dimension of the array A. LDA >= max(1,M).
*
* B (input) REAL array, dimension (LDB,N)
* The upper quasi-triangular matrix B, in Schur canonical form.
*
* LDB (input) INTEGER
* The leading dimension of the array B. LDB >= max(1,N).
*
* C (input/output) REAL array, dimension (LDC,N)
* On entry, the M-by-N right hand side matrix C.
* On exit, C is overwritten by the solution matrix X.
*
* LDC (input) INTEGER
* The leading dimension of the array C. LDC >= max(1,M)
*
* SCALE (output) REAL
* The scale factor, scale, set <= 1 to avoid overflow in X.
*
* INFO (output) INTEGER
* = 0: successful exit
* < 0: if INFO = -i, the i-th argument had an illegal value
* = 1: A and B have common or very close eigenvalues; perturbed
* values were used to solve the equation (but the matrices
* A and B are unchanged).
*
* =====================================================================
*
* .. Parameters ..
|
Method Summary |
static void |
STRSYL(java.lang.String trana,
java.lang.String tranb,
int isgn,
int m,
int n,
float[][] a,
float[][] b,
float[][] c,
floatW scale,
intW info)
|
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
STRSYL
public STRSYL()
STRSYL
public static void STRSYL(java.lang.String trana,
java.lang.String tranb,
int isgn,
int m,
int n,
float[][] a,
float[][] b,
float[][] c,
floatW scale,
intW info)