1DLASSQ(1)           LAPACK auxiliary routine (version 3.1)           DLASSQ(1)
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NAME

6       DLASSQ  -  the  values  scl and smsq such that   ( scl**2 )*smsq = x( 1
7       )**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
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21       where  x( i ) = X( 1 + ( i - 1  )*INCX  ).  The  value  of   sumsq   is
22       assumed to be non-negative and  scl  returns the value
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24          scl = max( scale, abs( x( i ) ) ).
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26       scale and sumsq must be supplied in SCALE and SUMSQ and
27       scl and smsq are overwritten on SCALE and SUMSQ respectively.
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29       The routine makes only one pass through the vector x.
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ARGUMENTS

33       N       (input) INTEGER
34               The number of elements to be used from the vector X.
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36       X       (input) DOUBLE PRECISION array, dimension (N)
37               The vector for which a scaled sum of squares is computed.  x( i
38               )  = X( 1 + ( i - 1 )*INCX ), 1 <= i <= n.
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40       INCX    (input) INTEGER
41               The increment between successive values of the vector X.   INCX
42               > 0.
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44       SCALE   (input/output) DOUBLE PRECISION
45               On  entry,  the  value  scale  in the equation above.  On exit,
46               SCALE is overwritten with  scl , the scaling factor for the sum
47               of squares.
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49       SUMSQ   (input/output) DOUBLE PRECISION
50               On  entry,  the  value  sumsq  in the equation above.  On exit,
51               SUMSQ is overwritten with  smsq , the basic sum of squares from
52               which  scl  has been factored out.
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56 LAPACK auxiliary routine (versionNo3v.e1m)ber 2006                       DLASSQ(1)