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INTEGER FUNCTION ISAMAX(N,SX,INCX)
* .. Scalar Arguments ..
INTEGER INCX,N
* ..
* .. Array Arguments ..
REAL SX(*)
* ..
*
* Purpose
* =======
*
* finds the index of element having max. absolute value.
* 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
* ..
* .. Intrinsic Functions ..
INTRINSIC ABS
* ..
ISAMAX = 0
IF (N.LT.1 .OR. INCX.LE.0) RETURN
ISAMAX = 1
IF (N.EQ.1) RETURN
IF (INCX.EQ.1) GO TO 20
*
* code for increment not equal to 1
*
IX = 1
SMAX = ABS(SX(1))
IX = IX + INCX
DO 10 I = 2,N
IF (ABS(SX(IX)).LE.SMAX) GO TO 5
ISAMAX = I
SMAX = ABS(SX(IX))
5 IX = IX + INCX
10 CONTINUE
RETURN
*
* code for increment equal to 1
*
20 SMAX = ABS(SX(1))
DO 30 I = 2,N
IF (ABS(SX(I)).LE.SMAX) GO TO 30
ISAMAX = I
SMAX = ABS(SX(I))
30 CONTINUE
RETURN
END
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