ADAS Subroutine diag

C
      SUBROUTINE DIAG(N,Z,D)                                            
      IMPLICIT REAL*8(A-H,O-Z)                                          
C                                                                       
C PURPOSE: DIAGONALIZATION OF REAL SYMMETRIC N-BY-N MATRIX Z.           
C
C INPUT REQUIRED. N AND Z. ONLY LOWER TRIANGLE OF Z NEED BE SUPPLIED.   
C                          MATRIX Z OVERWRITTEN BY EIGENVECTORS OF Z.   
C OUTPUT.         Z AND D, WHERE Z CONSISTS OF COLUMN EIGENVECTORS      
C                          AND D CONSISTS OF CORRESPONDING EIGENVALUES. 
C N.B. THE VALUE OF N MUST NOT EXCEED THE DIMENSION OF THE VARIABLE E,  
C SPECIFIED IN THE FOLLOWING LINE.                                      
C                                                                       
C-------------------------------------------------------------------------
C
C  VERSION  : 1.1                          
C  DATE     : ?
C  MODIFIED : H P Summers 
C              - Initial version. 
C
C  VERSION  : 1.2                          
C  DATE     : 16-05-2007
C  MODIFIED : Allan Whiteford
C              - Remove listing information from colums 72+. 
C              - Updated comments as part of subroutine documentation
C	         procedure.
C-------------------------------------------------------------------------
      INTEGER             N
      REAL*8              D(10),       Z(10,10)