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INTEGER FUNCTION ICAMAX(N,CX,INCX)
* .. Scalar Arguments .. INTEGER INCX,N * .. * .. Array Arguments .. COMPLEX CX(*) * .. * * Purpose * ======= * * ICAMAX finds the index of element having max. absolute value. * * Further Details * =============== * * jack dongarra, linpack, 3/11/78. * modified 3/93 to return if incx .le. 0. * modified 12/3/93, array(1) declarations changed to array(*) * * ===================================================================== * * .. Local Scalars .. REAL SMAX INTEGER I,IX * .. * .. External Functions .. REAL SCABS1 EXTERNAL SCABS1 * .. ICAMAX = 0 IF (N.LT.1 .OR. INCX.LE.0) RETURN ICAMAX = 1 IF (N.EQ.1) RETURN IF (INCX.EQ.1) THEN * * code for increment equal to 1 * SMAX = SCABS1(CX(1)) DO I = 2,N IF (SCABS1(CX(I)).GT.SMAX) THEN ICAMAX = I SMAX = SCABS1(CX(I)) END IF END DO ELSE * * code for increment not equal to 1 * IX = 1 SMAX = SCABS1(CX(1)) IX = IX + INCX DO I = 2,N IF (SCABS1(CX(IX)).GT.SMAX) THEN ICAMAX = I SMAX = SCABS1(CX(IX)) END IF IX = IX + INCX END DO END IF RETURN END |