slasy2(3) [centos man page]

slasy2.f(3)							      LAPACK							       slasy2.f(3)

NAME

       slasy2.f -

SYNOPSIS

   Functions/Subroutines
       subroutine slasy2 (LTRANL, LTRANR, ISGN, N1, N2, TL, LDTL, TR, LDTR, B, LDB, SCALE, X, LDX, XNORM, INFO)
	   SLASY2 solves the Sylvester matrix equation where the matrices are of order 1 or 2.

Function/Subroutine Documentation
   subroutine slasy2 (logicalLTRANL, logicalLTRANR, integerISGN, integerN1, integerN2, real, dimension( ldtl, * )TL, integerLDTL, real, dimension(
       ldtr, * )TR, integerLDTR, real, dimension( ldb, * )B, integerLDB, realSCALE, real, dimension( ldx, * )X, integerLDX, realXNORM,
       integerINFO)
       SLASY2 solves the Sylvester matrix equation where the matrices are of order 1 or 2.

       Purpose:

	    SLASY2 solves for the N1 by N2 matrix X, 1 <= N1,N2 <= 2, in

		   op(TL)*X + ISGN*X*op(TR) = SCALE*B,

	    where TL is N1 by N1, TR is N2 by N2, B is N1 by N2, and ISGN = 1 or
	    -1.  op(T) = T or T**T, where T**T denotes the transpose of T.

       Parameters:
	   LTRANL

		     LTRANL is LOGICAL
		     On entry, LTRANL specifies the op(TL):
			= .FALSE., op(TL) = TL,
			= .TRUE., op(TL) = TL**T.

	   LTRANR

		     LTRANR is LOGICAL
		     On entry, LTRANR specifies the op(TR):
		       = .FALSE., op(TR) = TR,
		       = .TRUE., op(TR) = TR**T.

	   ISGN

		     ISGN is INTEGER
		     On entry, ISGN specifies the sign of the equation
		     as described before. ISGN may only be 1 or -1.

	   N1

		     N1 is INTEGER
		     On entry, N1 specifies the order of matrix TL.
		     N1 may only be 0, 1 or 2.

	   N2

		     N2 is INTEGER
		     On entry, N2 specifies the order of matrix TR.
		     N2 may only be 0, 1 or 2.

	   TL

		     TL is REAL array, dimension (LDTL,2)
		     On entry, TL contains an N1 by N1 matrix.

	   LDTL

		     LDTL is INTEGER
		     The leading dimension of the matrix TL. LDTL >= max(1,N1).

	   TR

		     TR is REAL array, dimension (LDTR,2)
		     On entry, TR contains an N2 by N2 matrix.

	   LDTR

		     LDTR is INTEGER
		     The leading dimension of the matrix TR. LDTR >= max(1,N2).

	   B

		     B is REAL array, dimension (LDB,2)
		     On entry, the N1 by N2 matrix B contains the right-hand
		     side of the equation.

	   LDB

		     LDB is INTEGER
		     The leading dimension of the matrix B. LDB >= max(1,N1).

	   SCALE

		     SCALE is REAL
		     On exit, SCALE contains the scale factor. SCALE is chosen
		     less than or equal to 1 to prevent the solution overflowing.

	   X

		     X is REAL array, dimension (LDX,2)
		     On exit, X contains the N1 by N2 solution.

	   LDX

		     LDX is INTEGER
		     The leading dimension of the matrix X. LDX >= max(1,N1).

	   XNORM

		     XNORM is REAL
		     On exit, XNORM is the infinity-norm of the solution.

	   INFO

		     INFO is INTEGER
		     On exit, INFO is set to
			0: successful exit.
			1: TL and TR have too close eigenvalues, so TL or
			   TR is perturbed to get a nonsingular equation.
		     NOTE: In the interests of speed, this routine does not
			   check the inputs for errors.

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   September 2012

       Definition at line 174 of file slasy2.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012						       slasy2.f(3)