* F08HQF Example Program Text * Mark 20 Revised. NAG Copyright 2001. * .. Parameters .. INTEGER NIN, NOUT PARAMETER (NIN=5,NOUT=6) INTEGER NMAX, LDZ, LDAB PARAMETER (NMAX=8,LDZ=NMAX,LDAB=NMAX) INTEGER LWORK, LIWORK, LRWORK PARAMETER (LWORK=2*NMAX*NMAX,LIWORK=5*NMAX+3, + LRWORK=2*NMAX*NMAX+5*NMAX+1) * .. Local Scalars .. INTEGER I, IFAIL, INFO, J, KD, N CHARACTER JOB, UPLO * .. Local Arrays .. COMPLEX *16 AB(LDAB,NMAX), WORK(LWORK), Z(LDZ,NMAX) DOUBLE PRECISION RWORK(LRWORK), W(NMAX) INTEGER IWORK(LIWORK) * .. External Subroutines .. EXTERNAL X04DAF, ZHBEVD * .. Intrinsic Functions .. INTRINSIC MAX, MIN * .. Executable Statements .. WRITE (NOUT,*) 'F08HQF Example Program Results' * Skip heading in data file READ (NIN,*) READ (NIN,*) N, KD IF (N.LE.NMAX) THEN * * Read A from data file * READ (NIN,*) UPLO IF (UPLO.EQ.'U') THEN DO 20 I = 1, N READ (NIN,*) (AB(KD+1+I-J,J),J=I,MIN(N,I+KD)) 20 CONTINUE ELSE IF (UPLO.EQ.'L') THEN DO 40 I = 1, N READ (NIN,*) (AB(1+I-J,J),J=MAX(1,I-KD),I) 40 CONTINUE END IF * READ (NIN,*) JOB * * Calculate all the eigenvalues and eigenvectors of A * CALL ZHBEVD(JOB,UPLO,N,KD,AB,LDAB,W,Z,LDZ,WORK,LWORK,RWORK, + LRWORK,IWORK,LIWORK,INFO) * WRITE (NOUT,*) IF (INFO.GT.0) THEN WRITE (NOUT,*) 'Failure to converge.' ELSE * * Print eigenvalues and eigenvectors * WRITE (NOUT,*) 'Eigenvalues' DO 60 I = 1, N WRITE (NOUT,99999) I, W(I) 60 CONTINUE WRITE (NOUT,*) IFAIL = 0 * CALL X04DAF('General',' ',N,N,Z,LDZ,'Eigenvectors',IFAIL) * END IF END IF STOP * 99999 FORMAT (3X,I5,5X,2F8.4) END