ZLANTR  -  return the value of the one norm, or the Frobe­
       nius norm, or the infinity norm, or the element of largest
       absolute value of a trapezoidal or triangular matrix A


SYNOPSIS

       DOUBLE PRECISION FUNCTION  ZLANTR( NORM, UPLO, DIAG, M, N,
                        A, LDA, WORK )

           CHARACTER    DIAG, NORM, UPLO

           INTEGER      LDA, M, N

           DOUBLE       PRECISION WORK( * )

           COMPLEX*16   A( LDA, * )


PURPOSE

       ZLANTR returns the value of the one norm, or the Frobenius
       norm,  or  the  infinity  norm,  or the element of largest
       absolute value of a trapezoidal or triangular matrix A.


DESCRIPTION

       ZLANTR returns the value

          ZLANTR = ( max(abs(A(i,j))), NORM = 'M' or 'm'
                   (
                   ( norm1(A),         NORM = '1', 'O' or 'o'
                   (
                   ( normI(A),         NORM = 'I' or 'i'
                   (
                   ( normF(A),         NORM = 'F',  'f',  'E'  or
       'e'

       where   norm1   denotes the  one norm of a matrix (maximum
       column sum), normI   denotes  the   infinity  norm   of  a
       matrix   (maximum  row sum) and normF  denotes the  Frobe­
       nius norm of a matrix (square root  of  sum  of  squares).
       Note that  max(abs(A(i,j)))  is not a  matrix norm.


ARGUMENTS

       NORM    (input) CHARACTER*1
               Specifies  the  value  to be returned in ZLANTR as
               described above.

       UPLO    (input) CHARACTER*1
               Specifies whether the matrix A is upper  or  lower
               trapezoidal.  = 'U':  Upper trapezoidal
               =  'L':  Lower trapezoidal Note that A is triangu­
               lar instead of trapezoidal if M = N.

       DIAG    (input) CHARACTER*1
               Specifies whether or not the  matrix  A  has  unit

               = 'U':  Unit diagonal

       M       (input) INTEGER
               The  number  of rows of the matrix A.  M >= 0, and
               if UPLO = 'U', M <= N.  When M = 0, ZLANTR is  set
               to zero.

       N       (input) INTEGER
               The  number  of  columns of the matrix A.  N >= 0,
               and if UPLO = 'L', N <= M.  When N = 0, ZLANTR  is
               set to zero.

       A       (input) COMPLEX*16 array, dimension (LDA,N)
               The  trapezoidal  matrix A (A is triangular if M =
               N).  If UPLO = 'U',  the  leading  m  by  n  upper
               trapezoidal part of the array A contains the upper
               trapezoidal matrix, and the strictly lower  trian­
               gular part of A is not referenced.  If UPLO = 'L',
               the leading m by n lower trapezoidal part  of  the
               array A contains the lower trapezoidal matrix, and
               the strictly upper triangular part  of  A  is  not
               referenced.  Note that when DIAG = 'U', the diago­
               nal elements of  A  are  not  referenced  and  are
               assumed to be one.

       LDA     (input) INTEGER
               The  leading  dimension  of  the  array A.  LDA >=
               max(M,1).

       WORK    (workspace) DOUBLE PRECISION array, dimension
               (LWORK),
               where  LWORK >= M when NORM = 'I'; otherwise, WORK
               is not referenced.


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