C C ________________________________________________________ C | | C | FIND ALL THE EIGENVALUES OF A SYMMETRIC BAND MATRIX | C | | C | INPUT: | C | | C | A --ARRAY CONTAINING COEFFICIENT MATRIX IN | C | COMPRESSED FORMAT | C | | C | LA --LEADING (ROW) DIMENSION OF ARRAY A | C | | C | N --MATRIX DIMENSION | C | | C | H --HALF BANDWIDTH | C | | C | W --WORK ARRAY WHICH CAN BE IDENTIFIED WITH| C | ARRAY A ALTHOUGH THE ORIGINAL COEFFI- | C | CIENTS WILL BE DESTROYED | C | (LENGTH AT LEAST (H+1)(N-.5H+6) - 12) | C | | C | OUTPUT: | C | | C | E --EIGENVALUES | C | | C | D --DIAGONAL OF REDUCED TRIDIAGONAL MATRIX | C | | C | U --SUPERDIAGONAL OF REDUCED MATRIX | C | | C | A --THE ORIGINAL A ARRAY IS UNTOUCHED | C | UNLESS W IS IDENTIFIED WITH A | C | | C | PACKAGE SUBROUTINES: HHESS,TVALS | C |________________________________________________________| C SUBROUTINE HVALS(E,D,U,A,LA,N,H,W) REAL A(1),D(1),E(1),U(1),W(1) INTEGER H,LA,N CALL HHESS(D,U,A,LA,N,H,W) CALL TVALS(E,U,D,U,N,W) RETURN END