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

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

     INTEGER INCX, N

     DOUBLE PRECISION SCALE, SUMSQ

     DOUBLE PRECISION X( * )



     #include <sunperf.h>

     void dlassq(int n, double x, int incx, double *dscale,  dou-
               ble *sumsq) ;

PURPOSE
     DLASSQ  returns the values  scl  and  smsq  such that

     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  respec-
     tively.

     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) DOUBLE PRECISION
               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) DOUBLE PRECISION
               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) DOUBLE PRECISION
               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.

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