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C
C ------------------------------------------------------------------
C
SUBROUTINE DMVPC(NBLOCK, BET, MAXJ, J, S, NUMBER, RESNRM,
* ORTHCF, RV)
C
INTEGER NBLOCK, MAXJ, J, NUMBER
DOUBLE PRECISION BET(NBLOCK,1), S(MAXJ,1), RESNRM(1),
* ORTHCF(1), RV(1)
C
C THIS SUBROUTINE COMPUTES THE NORM AND THE SMALLEST ELEMENT
C (IN ABSOLUTE VALUE) OF THE VECTOR BET*SJI, WHERE SJI
C IS AN NBLOCK VECTOR OF THE LAST NBLOCK ELEMENTS OF THE ITH
C EIGENVECTOR OF T. THESE QUANTITIES ARE THE RESIDUAL NORM
C AND THE ORTHOGONALITY COEFFICIENT RESPECTIVELY FOR THE
C CORRESPONDING RITZ PAIR. THE ORTHOGONALITY COEFFICIENT IS
C NORMALIZED TO ACCOUNT FOR THE LOCAL REORTHOGONALIZATION.
C
INTEGER I, K, M
DOUBLE PRECISION DDOT, DNRM2, DABS, DMIN1
C
M = J - NBLOCK + 1
DO 20 I=1,NUMBER
DO 10 K=1,NBLOCK
RV(K) = DDOT(NBLOCK,S(M,I),1,BET(K,1),NBLOCK)
IF (K.EQ.1) ORTHCF(I) = DABS(RV(K))
ORTHCF(I) = DMIN1(ORTHCF(I),DABS(RV(K)))
10 CONTINUE
RESNRM(I) = DNRM2(NBLOCK,RV,1)
20 CONTINUE
RETURN
END
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