49 lines
1.0 KiB
FortranFixed
49 lines
1.0 KiB
FortranFixed
DOUBLE PRECISION FUNCTION DZASUM(N,ZX,INCX)
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* .. Scalar Arguments ..
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INTEGER INCX,N
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* ..
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* .. Array Arguments ..
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DOUBLE COMPLEX ZX(*)
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* ..
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*
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* Purpose
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* =======
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*
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* takes the sum of the absolute values.
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* jack dongarra, 3/11/78.
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* modified 3/93 to return if incx .le. 0.
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* modified 12/3/93, array(1) declarations changed to array(*)
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*
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*
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* .. Local Scalars ..
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DOUBLE PRECISION STEMP
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INTEGER I,IX
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* ..
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* .. External Functions ..
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DOUBLE PRECISION DCABS1
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EXTERNAL DCABS1
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* ..
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DZASUM = 0.0d0
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STEMP = 0.0d0
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IF (N.LE.0 .OR. INCX.LE.0) RETURN
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IF (INCX.EQ.1) GO TO 20
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*
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* code for increment not equal to 1
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*
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IX = 1
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DO 10 I = 1,N
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STEMP = STEMP + DCABS1(ZX(IX))
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IX = IX + INCX
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10 CONTINUE
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DZASUM = STEMP
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RETURN
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*
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* code for increment equal to 1
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*
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20 DO 30 I = 1,N
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STEMP = STEMP + DCABS1(ZX(I))
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30 CONTINUE
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DZASUM = STEMP
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RETURN
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END
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