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

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

10       SUBROUTINE ZLASSQ( 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           COMPLEX*16     X( * )
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PURPOSE

19       ZLASSQ returns the values scl and ssq such that where x( i ) = abs(  X(
20       1  +  (  i - 1 )*INCX ) ). The value of sumsq is assumed to be at least
21       unity and the value of ssq will then satisfy
22          1.0 .le. ssq .le. ( sumsq + 2*n ).
23       scale is assumed to be non-negative and scl returns the value
24          scl = max( scale, abs( real( x( i ) ) ), abs( aimag( x( i ) ) ) ),
25                 i
26       scale and sumsq must be  supplied  in  SCALE  and  SUMSQ  respectively.
27       SCALE  and SUMSQ are overwritten by scl and ssq respectively.  The rou‐
28       tine makes only one pass through the vector X.
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ARGUMENTS

31       N       (input) INTEGER
32               The number of elements to be used from the vector X.
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34       X       (input) COMPLEX*16 array, dimension (N)
35               The vector x as described above.  x( i )  = X( 1  +  (  i  -  1
36               )*INCX ), 1 <= i <= n.
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38       INCX    (input) INTEGER
39               The  increment between successive values of the vector X.  INCX
40               > 0.
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42       SCALE   (input/output) DOUBLE PRECISION
43               On entry, the value  scale  in the equation  above.   On  exit,
44               SCALE is overwritten with the value  scl .
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46       SUMSQ   (input/output) DOUBLE PRECISION
47               On  entry,  the  value  sumsq  in the equation above.  On exit,
48               SUMSQ is overwritten with the value  ssq .
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52 LAPACK auxiliary routine (versionNo3v.e2m)ber 2008                       ZLASSQ(1)