SLARHS chooses a set of NRHS random solution vectors and sets


 up the right hand sides for the linear system


    op(A) * X = B,


 where op(A) = A or A**T, depending on TRANS.

PATH

          PATH is CHARACTER*3


          The type of the real matrix A.  PATH may be given in any


          combination of upper and lower case.  Valid types include


             xGE:  General m x n matrix


             xGB:  General banded matrix


             xPO:  Symmetric positive definite, 2-D storage


             xPP:  Symmetric positive definite packed


             xPB:  Symmetric positive definite banded


             xSY:  Symmetric indefinite, 2-D storage


             xSP:  Symmetric indefinite packed


             xSB:  Symmetric indefinite banded


             xTR:  Triangular


             xTP:  Triangular packed


             xTB:  Triangular banded


             xQR:  General m x n matrix


             xLQ:  General m x n matrix


             xQL:  General m x n matrix


             xRQ:  General m x n matrix


          where the leading character indicates the precision.

XTYPE

          XTYPE is CHARACTER*1


          Specifies how the exact solution X will be determined:


          = 'N':  New solution; generate a random X.


          = 'C':  Computed; use value of X on entry.

UPLO

          UPLO is CHARACTER*1


          Specifies whether the upper or lower triangular part of the


          matrix A is stored, if A is symmetric.


          = 'U':  Upper triangular


          = 'L':  Lower triangular

TRANS

          TRANS is CHARACTER*1


          Used only if A is nonsymmetric; specifies the operation


          applied to the matrix A.


          = 'N':  B := A    * X  (No transpose)


          = 'T':  B := A**T * X  (Transpose)


          = 'C':  B := A**H * X  (Conjugate transpose = Transpose)

M

          M is INTEGER


          The number or rows of the matrix A.  M >= 0.

N

          N is INTEGER


          The number of columns of the matrix A.  N >= 0.

KL

          KL is INTEGER


          Used only if A is a band matrix; specifies the number of


          subdiagonals of A if A is a general band matrix or if A is


          symmetric or triangular and UPLO = 'L'; specifies the number


          of superdiagonals of A if A is symmetric or triangular and


          UPLO = 'U'.  0 <= KL <= M-1.

KU

          KU is INTEGER


          Used only if A is a general band matrix or if A is


          triangular.


          If PATH = xGB, specifies the number of superdiagonals of A,


          and 0 <= KU <= N-1.


          If PATH = xTR, xTP, or xTB, specifies whether or not the


          matrix has unit diagonal:


          = 1:  matrix has non-unit diagonal (default)


          = 2:  matrix has unit diagonal

NRHS

          NRHS is INTEGER


          The number of right hand side vectors in the system A*X = B.

A

          A is REAL array, dimension (LDA,N)


          The test matrix whose type is given by PATH.

LDA

          LDA is INTEGER


          The leading dimension of the array A.


          If PATH = xGB, LDA >= KL+KU+1.


          If PATH = xPB, xSB, xHB, or xTB, LDA >= KL+1.


          Otherwise, LDA >= max(1,M).

X

          X is or output) REAL array, dimension(LDX,NRHS)


          On entry, if XTYPE = 'C' (for 'Computed'), then X contains


          the exact solution to the system of linear equations.


          On exit, if XTYPE = 'N' (for 'New'), then X is initialized


          with random values.

LDX

          LDX is INTEGER


          The leading dimension of the array X.  If TRANS = 'N',


          LDX >= max(1,N); if TRANS = 'T', LDX >= max(1,M).

B

          B is REAL array, dimension (LDB,NRHS)


          The right hand side vector(s) for the system of equations,


          computed from B = op(A) * X, where op(A) is determined by


          TRANS.

LDB

          LDB is INTEGER


          The leading dimension of the array B.  If TRANS = 'N',


          LDB >= max(1,M); if TRANS = 'T', LDB >= max(1,N).

ISEED

          ISEED is INTEGER array, dimension (4)


          The seed vector for the random number generator (used in


          SLATMS).  Modified on exit.

INFO

          INFO is INTEGER


          = 0: successful exit


          < 0: if INFO = -i, the i-th argument had an illegal value

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