47 lines
1.3 KiB
Plaintext
47 lines
1.3 KiB
Plaintext
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PROGRAM REDBF
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PARAMETER (N=10)
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REAL A(N,N), EPS, MAXEXP, W
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INTEGER ITMAX
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CDVM$ DISTRIBUTE A(BLOCK, BLOCK)
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PRINT *, '********** TEST_REDBLACK **********'
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ITMAX = 20
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MAXEXP = 0.5E - 5
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W = 0.5
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CDVM$ PARALLEL (J,I) ON A(I, J)
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DO 1 J = 1,N
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DO 1 I = 1,N
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IF (I.EQ.J) THEN
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A(I,J) = N+2
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ELSE
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A(I,J) = -1.
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ENDIF
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1 CONTINUE
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DO 2 IT = 1, ITMAX
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EPS = 0.
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C loop for red and black variables
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DO 3 IRB = 0,1
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CDVM$ PARALLEL (J,I) ON A(I, J), NEW (S), REDUCTION (MAX(EPS)),
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CDVM$* SHADOW_RENEW (A)
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C variable S - private variable in loop iterations
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C variable EPS is used for calculation of maximum value
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C Exception : iteration space is not rectangular
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DO 21 J = 2,N-1
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DO 21 I = 2 + MOD(J+IRB,2), N-1, 2
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S = A(I,J)
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A(I,J) = (W/4) * (A(I-1,J) + A(I+1,J) + A(I,J-1) +
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* A(I,J+1)) + (1-W) * A(I,J)
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EPS = MAX (EPS, ABS(S - A(I,J)))
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21 CONTINUE
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3 CONTINUE
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PRINT 200, IT, EPS
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200 FORMAT(' IT = ',I4, ' EPS = ', E14.7)
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IF (EPS.LT.MAXEXP) GO TO 4
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2 CONTINUE
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4 OPEN (3, FILE='REDBF.DAT', FORM='FORMATTED',STATUS='UNKNOWN')
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WRITE (3,*) A
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CLOSE (3)
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END
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