* F07GWF Example Program Text * Mark 15 Release. NAG Copyright 1991. * .. Parameters .. INTEGER NIN, NOUT PARAMETER (NIN=5,NOUT=6) INTEGER NMAX PARAMETER (NMAX=8) * .. Local Scalars .. INTEGER I, IFAIL, INFO, J, N CHARACTER UPLO * .. Local Arrays .. COMPLEX *16 AP(NMAX*(NMAX+1)/2) CHARACTER CLABS(1), RLABS(1) * .. External Subroutines .. EXTERNAL X04DDF, ZPPTRF, ZPPTRI * .. Executable Statements .. WRITE (NOUT,*) 'F07GWF Example Program Results' * Skip heading in data file READ (NIN,*) READ (NIN,*) N IF (N.LE.NMAX) THEN * * Read A from data file * READ (NIN,*) UPLO IF (UPLO.EQ.'U') THEN READ (NIN,*) ((AP(I+J*(J-1)/2),J=I,N),I=1,N) ELSE IF (UPLO.EQ.'L') THEN READ (NIN,*) ((AP(I+(2*N-J)*(J-1)/2),J=1,I),I=1,N) END IF * * Factorize A * CALL ZPPTRF(UPLO,N,AP,INFO) * WRITE (NOUT,*) IF (INFO.EQ.0) THEN * * Compute inverse of A * CALL ZPPTRI(UPLO,N,AP,INFO) * * Print inverse * IFAIL = 0 CALL X04DDF(UPLO,'Nonunit',N,AP,'Bracketed','F7.4', + 'Inverse','Integer',RLABS,'Integer',CLABS,80,0, + IFAIL) ELSE WRITE (NOUT,*) 'A is not positive-definite' END IF END IF STOP * END