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REAL FUNCTION SCNRM2( N, X, INCX )
* .. Scalar Arguments ..
INTEGER INCX, N
* .. Array Arguments ..
COMPLEX X( * )
* ..
*
* SCNRM2 returns the euclidean norm of a vector via the function
* name, so that
*
* SCNRM2 := sqrt( conjg( x' )*x )
*
*
*
* -- This version written on 25-October-1982.
* Modified on 14-October-1993 to inline the call to CLASSQ.
* Sven Hammarling, Nag Ltd.
*
*
* .. Parameters ..
REAL ONE , ZERO
PARAMETER ( ONE = 1.0E+0, ZERO = 0.0E+0 )
* .. Local Scalars ..
INTEGER IX
REAL NORM, SCALE, SSQ, TEMP
* .. Intrinsic Functions ..
INTRINSIC ABS, AIMAG, REAL, SQRT
* ..
* .. Executable Statements ..
IF( N.LT.1 .OR. INCX.LT.1 )THEN
NORM = ZERO
ELSE
SCALE = ZERO
SSQ = ONE
* The following loop is equivalent to this call to the LAPACK
* auxiliary routine:
* CALL CLASSQ( N, X, INCX, SCALE, SSQ )
*
DO 10, IX = 1, 1 + ( N - 1 )*INCX, INCX
IF( REAL( X( IX ) ).NE.ZERO )THEN
TEMP = ABS( REAL( X( IX ) ) )
IF( SCALE.LT.TEMP )THEN
SSQ = ONE + SSQ*( SCALE/TEMP )**2
SCALE = TEMP
ELSE
SSQ = SSQ + ( TEMP/SCALE )**2
END IF
END IF
IF( AIMAG( X( IX ) ).NE.ZERO )THEN
TEMP = ABS( AIMAG( X( IX ) ) )
IF( SCALE.LT.TEMP )THEN
SSQ = ONE + SSQ*( SCALE/TEMP )**2
SCALE = TEMP
ELSE
SSQ = SSQ + ( TEMP/SCALE )**2
END IF
END IF
10 CONTINUE
NORM = SCALE * SQRT( SSQ )
END IF
*
SCNRM2 = NORM
RETURN
*
* End of SCNRM2.
*
END
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