 
      SUBROUTINE STAND(MM, M, N, A)
C
C<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
C
C   PURPOSE
C   -------
C
C      STANDARDIZES A DATA MATRIX SUCH THAT EACH VARIABLE HAS MEAN ZERO
C      AND UNIT VARIANCE.  MISSING VALUES ARE IGNORED
C
C   INPUT PARAMETERS
C   ----------------
C
C   MM    INTEGER SCALAR (UNCHANGED ON OUTPUT).
C         THE FIRST DIMENSION OF THE MATRIX A.  MUST BE AT LEAST M.
C
C   M     INTEGER SCALAR (UNCHANGED ON OUTPUT).
C         THE NUMBER OF CASES.
C
C   N     INTEGER SCALAR (UNCHANGED ON OUTPUT).
C         THE NUMBER OF VARIABLES.
C
C   A     REAL MATRIX WHOSE FIRST DIMENSION MUST BE MM AND WHOSE SECOND
C            DIMENSION MUST BE AT LEAST N (CHANGED ON OUTPUT).
C         THE MATRIX OF DATA VALUES.
C
C         A(I,J) IS THE VALUE FOR THE J-TH VARIABLE FOR THE I-TH CASE.
C
C   OUTPUT PARAMETER
C   ----------------
C
C   A     REAL MATRIX WHOSE FIRST DIMENSION MUST BE MM AND WHOSE SECOND
C            DIMENSION MUST BE AT LEAST N.
C         THE STANDARDIZED MATRIX OF DATA VALUES.
C
C   REFERENCE
C   ---------
C
C     HARTIGAN, J. A. (1975).  CLUSTERING ALGORITHMS, JOHN WILEY &
C        SONS, INC., NEW YORK.  PAGES 69, 73.
C
C<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
C
 
 
