C C ________________________________________________________ C | | C | COMPUTE THE DIAGONALIZATION OF A REAL SYMMETRIC MATRIX | C | | C | INPUT: | C | | C | LV --LEADING (ROW) DIMENSION OF ARRAY V | C | | C | A --ARRAY PACKED WITH ELEMENTS CONTAINED | C | IN EACH ROW, ON DIAGONAL AND TO RIGHT, | C | OF COEFFICIENT MATRIX | C | FORMAT (LENGTH AT LEAST N(N+3)/2) | C | | C | N --MATRIX DIMENSION | C | | C | W --WORK ARRAY WITH AT LEAST 2N ELEMENTS | C | | C | OUTPUT: | C | | C | E --ARRAY OF EIGENVALUES | C | | C | V --ARRAY OF EIGENVECTORS | C | | C | A --OUTPUT OF SHESS | C | | C | PACKAGE SUBROUTINES: SHESS,SSIM,TDG | C |________________________________________________________| C SUBROUTINE SDIAG(E,V,LV,A,N,W) REAL A(1),E(1),V(1),W(1) INTEGER LV,M,N M = N + 1 C ------------------------------------ C |*** REDUCE TO TRIDIAGONAL FORM ***| C ------------------------------------ CALL SHESS(W,W(M),A,N) C ----------------------------------------------- C |*** COMPUTE THE SIMILARITY TRANSFORMATION ***| C ----------------------------------------------- CALL SSIM(V,LV,A) C -------------------------------------------- C |*** DIAGONALIZE THE TRIDIAGONAL MATRIX ***| C -------------------------------------------- CALL TDG(E,V,LV,W,W(M),N) RETURN END