INTEGER FUNCTION IZAMAX(N,ZX,INCX) * .. Scalar Arguments .. INTEGER INCX,N * .. * .. Array Arguments .. DOUBLE COMPLEX ZX(*) * .. * * Purpose * ======= * * IZAMAX finds the index of element having max. absolute value. * * Further Details * =============== * * jack dongarra, 1/15/85. * modified 3/93 to return if incx .le. 0. * modified 12/3/93, array(1) declarations changed to array(*) * * ===================================================================== * * .. Local Scalars .. DOUBLE PRECISION DMAX INTEGER I,IX * .. * .. External Functions .. DOUBLE PRECISION DCABS1 EXTERNAL DCABS1 * .. IZAMAX = 0 IF (N.LT.1 .OR. INCX.LE.0) RETURN IZAMAX = 1 IF (N.EQ.1) RETURN IF (INCX.EQ.1) THEN * * code for increment equal to 1 * DMAX = DCABS1(ZX(1)) DO I = 2,N IF (DCABS1(ZX(I)).GT.DMAX) THEN IZAMAX = I DMAX = DCABS1(ZX(I)) END IF END DO ELSE * * code for increment not equal to 1 * IX = 1 DMAX = DCABS1(ZX(1)) IX = IX + INCX DO I = 2,N IF (DCABS1(ZX(IX)).GT.DMAX) THEN IZAMAX = I DMAX = DCABS1(ZX(IX)) END IF IX = IX + INCX END DO END IF RETURN END