redhat man page for slassq

SLASSQ(l)								 )								 SLASSQ(l)

NAME
       SLASSQ - return the values scl and smsq such that  ( scl**2 )*smsq = x( 1 )**2 +...+ x( n )**2 + ( scale**2 )*sumsq,

SYNOPSIS
       SUBROUTINE SLASSQ( N, X, INCX, SCALE, SUMSQ )

	   INTEGER	  INCX, N

	   REAL 	  SCALE, SUMSQ

	   REAL 	  X( * )

PURPOSE
       SLASSQ returns the values scl and smsq such that ( scl**2 )*smsq = x( 1 )**2 +...+ x( n )**2 + ( scale**2 )*sumsq, where  x( i ) = X( 1 + (
       i - 1 )*INCX ). The value of  sumsq  is assumed to be non-negative and  scl  returns the value

	  scl = max( scale, abs( x( i ) ) ).

       scale and sumsq must be supplied in SCALE and SUMSQ and
       scl and smsq are overwritten on SCALE and SUMSQ respectively.

       The routine makes only one pass through the vector x.

ARGUMENTS
       N       (input) INTEGER
	       The number of elements to be used from the vector X.

       X       (input) REAL array, dimension (N)
	       The vector for which a scaled sum of squares is computed.  x( i )  = X( 1 + ( i - 1 )*INCX ), 1 <= i <= n.

       INCX    (input) INTEGER
	       The increment between successive values of the vector X.  INCX > 0.

       SCALE   (input/output) REAL
	       On entry, the value  scale  in the equation above.  On exit, SCALE is overwritten with  scl , the scaling factor  for  the  sum	of
	       squares.

       SUMSQ   (input/output) REAL
	       On  entry, the value  sumsq  in the equation above.  On exit, SUMSQ is overwritten with	smsq , the basic sum of squares from which
	       scl  has been factored out.

LAPACK version 3.0						   15 June 2000 							 SLASSQ(l)