1DLASSQ(1)           LAPACK auxiliary routine (version 3.2)           DLASSQ(1)
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NAME

6       DLASSQ  - returns the values scl and smsq such that   ( scl**2 )*smsq =
7       x( 1 )**2 +...+ x( n )**2 + ( scale**2 )*sumsq,
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SYNOPSIS

10       SUBROUTINE DLASSQ( N, X, INCX, SCALE, SUMSQ )
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12           INTEGER        INCX, N
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14           DOUBLE         PRECISION SCALE, SUMSQ
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16           DOUBLE         PRECISION X( * )
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PURPOSE

19       DLASSQ  returns the values  scl  and  smsq  such that where  x( i  )  =
20       X( 1 + ( i - 1 )*INCX ). The value of  sumsq  is assumed to be non-neg‐
21       ative and  scl  returns the value
22          scl = max( scale, abs( x( i ) ) ).
23       scale and sumsq must be supplied in SCALE and SUMSQ and
24       scl and smsq are overwritten on SCALE and SUMSQ respectively.  The rou‐
25       tine makes only one pass through the vector x.
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ARGUMENTS

28       N       (input) INTEGER
29               The number of elements to be used from the vector X.
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31       X       (input) DOUBLE PRECISION array, dimension (N)
32               The vector for which a scaled sum of squares is computed.  x( i
33               )  = X( 1 + ( i - 1 )*INCX ), 1 <= i <= n.
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35       INCX    (input) INTEGER
36               The increment between successive values of the vector X.   INCX
37               > 0.
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39       SCALE   (input/output) DOUBLE PRECISION
40               On  entry,  the  value  scale  in the equation above.  On exit,
41               SCALE is overwritten with  scl , the scaling factor for the sum
42               of squares.
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44       SUMSQ   (input/output) DOUBLE PRECISION
45               On  entry,  the  value  sumsq  in the equation above.  On exit,
46               SUMSQ is overwritten with  smsq , the basic sum of squares from
47               which  scl  has been factored out.
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51 LAPACK auxiliary routine (versionNo3v.e2m)ber 2008                       DLASSQ(1)