      SUBROUTINE DEFINE(X,N,XNEW)
C
C     PURPOSE--THIS SUBROUTINE SETS ALL OF THE ELEMENTS
C              IN THE SINGLE PRECISION VECTOR X
C              EQUAL TO XNEW. 
C              THIS SUBROUTINE IS USEFUL IN DEFINING A
C              VECTOR OF CONSTANTS.
C              FOR EXAMPLE, IF THE DATA ANALYST WISHES
C              TO TREAT THE EQUAL WEIGHTS CASE IN DOING
C              A POLYNOMIAL REGRESSION, THIS COULD
C              BE DONE BY DEFINING AS, SAY, 1.0
C              THE INPUT WEIGHT VECTOR W TO THE
C              DATAPAC POLY SUBROUTINE; 
C              SUCH DEFINING COULD BE DONE
C              BY USE OF THE DEFINE SUBROUTINE
C              WITH XNEW = 1.0.
C     INPUT  ARGUMENTS--X      = THE SINGLE PRECISION VECTOR OF
C                                (UNSORTED OR SORTED) OBSERVATIONS.
C                     --N      = THE INTEGER NUMBER OF OBSERVATIONS
C                                IN THE VECTOR X. 
C                     --XNEW   = THE SINGLE PRECISION VALUE 
C                                TO WHICH ALL OF THE
C                                OBSERVATIONS IN THE VECTOR X
C                                WILL BE SET.
C     OUTPUT--THE SINGLE PRECISION VECTOR X
C             EVERY ELEMENT OF WHICH
C             WILL BE EQUAL TO XNEW.
C             ALSO, 3 LINES OF SUMMARY INFORMATION
C             WILL BE GENERATED INDICATING
C             1) WHAT THE SAMPLE SIZE WAS (N);
C             2) WHAT THE DEFINING CONSTANT WAS (XNEW);
C     PRINTING--YES.
C     RESTRICTIONS--THERE IS NO RESTRICTION ON THE MAXIMUM VALUE
C                   OF N FOR THIS SUBROUTINE.
C     OTHER DATAPAC   SUBROUTINES NEEDED--NONE.
C     FORTRAN LIBRARY SUBROUTINES NEEDED--NONE.
C     MODE OF INTERNAL OPERATIONS--SINGLE PRECISION.
C     LANGUAGE--ANSI FORTRAN. 
C     REFERENCES--NONE.
C     WRITTEN BY--JAMES J. FILLIBEN
C                 STATISTICAL ENGINEERING LABORATORY (205.03)
C                 NATIONAL BUREAU OF STANDARDS
C                 WASHINGTON, D. C. 20234
C                 PHONE--301-921-2315
C     ORIGINAL VERSION--NOVEMBER  1975. 
C     UPDATED  VERSION--JULY      1976. 
C
C---------------------------------------------------------------------
C
      DIMENSION X(1)
C
      IPR=6
C
C     CHECK THE INPUT ARGUMENTS FOR ERRORS
C
      IF(N.LT.1)GOTO50
      IF(N.EQ.1)GOTO55
      GOTO90
   50 WRITE(IPR,15) 
      WRITE(IPR,47)N
      RETURN
   55 WRITE(IPR,18) 
   90 CONTINUE
   15 FORMAT(1H , 91H***** FATAL ERROR--THE SECOND INPUT ARGUMENT TO THE
     1 DEFINE SUBROUTINE IS NON-POSITIVE *****)
   18 FORMAT(1H ,100H***** NON-FATAL DIAGNOSTIC--THE SECOND INPUT ARGUME
     1NT TO THE DEFINE SUBROUTINE HAS THE VALUE 1 *****)
   47 FORMAT(1H , 35H***** THE VALUE OF THE ARGUMENT IS ,I8   ,6H *****)
C
C-----START POINT-----------------------------------------------------
C
      DO100I=1,N
      X(I)=XNEW
  100 CONTINUE
C
C     WRITE OUT A BRIEF SUMMARY
C
      WRITE(IPR,999)
      WRITE(IPR,101)
      WRITE(IPR,110)N
      WRITE(IPR,111)XNEW
  101 FORMAT(1H ,35HOUTPUT FROM THE DEFINE SUBROUTINE--)
  110 FORMAT(1H ,7X,38HTHE INPUT  NUMBER OF OBSERVATIONS  IS ,I6)
  111 FORMAT(1H ,7X,25HTHE DEFINING CONSTANT IS ,E15.8)
  999 FORMAT(1H )
C
      RETURN
      END 
