ZLAROR pre- or post-multiplies an M by N matrix A by a random


    unitary matrix U, overwriting A. A may optionally be


    initialized to the identity matrix before multiplying by U.


    U is generated using the method of G.W. Stewart


    ( SIAM J. Numer. Anal. 17, 1980, pp. 403-409 ).


    (BLAS-2 version)

SIDE

          SIDE is CHARACTER*1


           SIDE specifies whether A is multiplied on the left or right


           by U.


       SIDE = 'L'   Multiply A on the left (premultiply) by U


       SIDE = 'R'   Multiply A on the right (postmultiply) by UC>       SIDE = 'C'   Multiply A on the left by U and the right by UC>       SIDE = 'T'   Multiply A on the left by U and the right by U'


           Not modified.

INIT

          INIT is CHARACTER*1


           INIT specifies whether or not A should be initialized to


           the identity matrix.


              INIT = 'I'   Initialize A to (a section of) the


                           identity matrix before applying U.


              INIT = 'N'   No initialization.  Apply U to the


                           input matrix A.


           INIT = 'I' may be used to generate square (i.e., unitary)


           or rectangular orthogonal matrices (orthogonality being


           in the sense of ZDOTC):


           For square matrices, M=N, and SIDE many be either 'L' or


           'R'; the rows will be orthogonal to each other, as will the


           columns.


           For rectangular matrices where M < N, SIDE = 'R' will


           produce a dense matrix whose rows will be orthogonal and


           whose columns will not, while SIDE = 'L' will produce a


           matrix whose rows will be orthogonal, and whose first M


           columns will be orthogonal, the remaining columns being


           zero.


           For matrices where M > N, just use the previous


           explanation, interchanging 'L' and 'R' and 'rows' and


           'columns'.


           Not modified.

M

          M is INTEGER


           Number of rows of A. Not modified.

N

          N is INTEGER


           Number of columns of A. Not modified.

A

           A is COMPLEX*16 array, dimension ( LDA, N )


           Input and output array. Overwritten by U A ( if SIDE = 'L' )


           or by A U ( if SIDE = 'R' )


           or by U A U* ( if SIDE = 'C')


           or by U A U' ( if SIDE = 'T') on exit.

LDA

          LDA is INTEGER


           Leading dimension of A. Must be at least MAX ( 1, M ).


           Not modified.

ISEED

          ISEED is INTEGER array, dimension ( 4 )


           On entry ISEED specifies the seed of the random number


           generator. The array elements should be between 0 and 4095;


           if not they will be reduced mod 4096.  Also, ISEED(4) must


           be odd.  The random number generator uses a linear


           congruential sequence limited to small integers, and so


           should produce machine independent random numbers. The


           values of ISEED are changed on exit, and can be used in the


           next call to ZLAROR to continue the same random number


           sequence.


           Modified.

X

          X is COMPLEX*16 array, dimension ( 3*MAX( M, N ) )


           Workspace. Of length:


               2*M + N if SIDE = 'L',


               2*N + M if SIDE = 'R',


               3*N     if SIDE = 'C' or 'T'.


           Modified.

INFO

          INFO is INTEGER


           An error flag.  It is set to:


            0  if no error.


            1  if ZLARND returned a bad random number (installation


               problem)


           -1  if SIDE is not L, R, C, or T.


           -3  if M is negative.


           -4  if N is negative or if SIDE is C or T and N is not equal


               to M.


           -6  if LDA is less than M.

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