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SUBROUTINE DMATX

PURPOSE
   COMPUTE MEANS OF VARIABLES IN EACH GROUP AND A POOLED
   DISPERSION MATRIX FOR ALL THE GROUPS. NORMALLY THIS SUB-
   ROUTINE IS USED IN THE PERFORMANCE OF DISCRIMINANT ANALYSIS.

USAGE
   CALL DMATX (K,M,N,X,XBAR,D,CMEAN)

DESCRIPTION OF PARAMETERS
   K	 - NUMBER OF GROUPS
   M	 - NUMBER OF VARIABLES (MUST BE THE SAME FOR ALL
	   GROUPS).
   N	 - INPUT VECTOR OF LENGTH K CONTAINING SAMPLE SIZES OF
	   GROUPS.
   X	 - INPUT VECTOR CONTAINING DATA IN THE MANNER EQUIVA-
	   LENT TO A 3-DIMENSIONAL FORTRAN ARRAY, X(1,1,1),
	   X(2,1,1), X(3,1,1), ETC.  THE FIRST SUBSCRIPT IS
	   CASE NUMBER, THE SECOND SUBSCRIPT IS VARIABLE NUMBER
	   AND THE THIRD SUBSCRIPT IS GROUP NUMBER.  THE
	   LENGTH OF VECTOR X IS EQUAL TO THE TOTAL NUMBER OF
	   DATA POINTS, T*M, WHERE T = N(1)+N(2)+...+N(K).
   XBAR  - OUTPUT MATRIX (M X K) CONTAINING MEANS OF VARIABLES
	   IN K GROUPS.
   D	 - OUTPUT MATRIX (M X M) CONTAINING POOLED DISPERSION.
   CMEAN - WORKING VECTOR OF LENGTH M.

REMARKS
   THE NUMBER OF VARIABLES MUST BE GREATER THAN OR EQUAL TO
   THE NUMBER OF GROUPS.

SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED
   NONE

METHOD
   REFER TO 'BMD COMPUTER PROGRAMS MANUAL', EDITED BY W. J.
   DIXON, UCLA, 1964, AND T. W. ANDERSON, 'INTRODUCTION TO
   MULTIVARIATE STATISTICAL ANALYSIS', JOHN WILEY AND SONS,
   1958, SECTION 6.6-6.8.